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Vol. 72. Issue 5.
Pages 373-382 (May 2019)
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Vol. 72. Issue 5.
Pages 373-382 (May 2019)
Original Article
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Procedural, Functional and Prognostic Outcomes Following Recanalization of Coronary Chronic Total Occlusions. Results of the Iberian Registry
Resultados inmediatos e impacto funcional y pronóstico tras la recanalización de oclusiones coronarias crónicas. Resultados del Registro Ibérico
Ignacio J. Amat-Santosa,
Corresponding author

Corresponding author: Servicio de Cardiología, Hospital Clínico Universitario, Ramón y Cajal 3, 47005 Valladolid, Spain.
, Victoria Martin-Yusteb, José Antonio Fernández-Díazc, Javier Martin-Moreirasd, Juan Caballero-Borregoe, Pablo Salinasf, Soledad Ojedag, Fernando Riveroh, Julio Núñez Villotai, Mohsen Mohandesj, Daniela Duboisk, Francisco Bosa Ojedal, Eva Rumizm, José M. de la Torre Hernándezn, Jesús Jiménez-Mazuecoso, Javier Lacunzap, Paula Tejedorq, Itziar Gómeza, Luis R. Goncalves-Ramireza, Paol Rojasa, Manel Sabatéb, Javier Goicoleac, Alejandro Diego Nietod, Miriam Jiménez-Fernándeze, Javier Escanedf, Nieves Gonzalof, Laura Pardog, Javier Cuestah, Gema Miñanai, Juan Sanchisi, Sergio Rojasj, Raúl Millánk, Beatriz Vaquerizok, Sara Rodríguezl, Dae-Hyun Leen, Francisco J. Moralesr, Alejandro Gutiérrezs, María Lópezt, Jaume Maristanyu, Juan Rondánv, Guillermo Galeotew, Zuheir Kabbannix, Sergio Rodríguezy, Luis Teruelz, Mario Sadabaaa, Alfonso Juradoab, Vicente Mainarac, Juan Sánchez-Rubioad, Hugo Vinhasae, Renato Fernandesaf
a Servicio de Cardiología, Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), Hospital Clínico Universitario, Valladolid, Spain
b Servicio de Cardiología, Hospital Clínic de Barcelona, Barcelona, Spain
c Servicio de Cardiología, Hospital Puerta de Hierro, Majadahonda, Madrid, Spain
d Servicio de Cardiología, Hospital Clínico Universitario de Salamanca, Salamanca, Spain
e Servicio de Cardiología, Hospital Campus de la Salud y Virgen de las Nieves, Granada, Spain
f Servicio de Cardiología, Hospital Clínico San Carlos, Madrid, Spain
g Servicio de Cardiología, Hospital Reina Sofía de Córdoba, Córdoba, Spain
h Servicio de Cardiología, Hospital La Princesa, Madrid, Spain
i Servicio de Cardiología, Centro de Investigación Biomédica en Red de Enfermedades Cardiovasculares (CIBERCV), Hospital Clínic Universitari, INCLIVA, Universitat de València, Valencia, Spain
j Servicio de Cardiología, Hospital de Tarragona, Tarragona, Spain
k Servicio de Cardiología, Hospital del Mar, Barcelona, Spain
l Servicio de Cardiología, Hospital de Tenerife, Santa Cruz de Tenerife, Spain
m Servicio de Cardiología, Hospital General de Valencia, Valencia, Spain
n Servicio de Cardiología, Hospital Marqués de Valdecilla, Santander, Cantabria, Spain
o Servicio de Cardiología, Hospital Clínico Universitario de Albacete, Albacete, Spain
p Servicio de Cardiología, Hospital de Murcia, Murcia, Spain
q Servicio de Cardiología, Complejo Hospitalario de Burgos, Burgos, Spain
r Servicio de Cardiología, Hospital Universitario Puerto Real, Puerto Real, Cádiz, Spain
s Servicio de Cardiología, Hospital de Jerez de la Frontera, Jerez de la Frontera, Cádiz, Spain
t Servicio de Cardiología, Hospital de León, León, Spain
u Servicio de Cardiología, Hospital Son Espases, Palma de Mallorca, Balearic Islands, Spain
v Servicio de Cardiología, Hospital de Cabueñes, Gijón, Asturias, Spain
w Servicio de Cardiología, Hospital de La Paz, Madrid, Spain
x Servicio de Cardiología, Hospital Hospiten, Santa Cruz de Tenerife, Spain
y Servicio de Cardiología, Hospital Virgen Macarena, Sevilla, Spain
z Servicio de Cardiología, Hospital de Bellvitge, L’Hospitalet de Llobregat, Barcelona, Spain
aa Servicio de Cardiología, Hospital Galdakao, Galdakao, Vizcaya, Spain
ab Servicio de Cardiología, Hospital de Ciudad Real, Ciudad Real, Spain
ac Servicio de Cardiología, Hospital de Alicante, Alicante, Spain
ad Servicio de Cardiología, Hospital Clínico de Zaragoza, Zaragoza, Spain
ae Servicio de Cardiología, Hospital García de Orta, Almada, Portugal
af Servicio de Cardiología, Hospital Espírito Santo, Evora, Portugal
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Paul Fefer
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Figures (3)
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Tables (4)
Table 1. Clinical, Anatomic, Procedure, and Inpatient Characteristics and Main Predictors of Angiographic Success
Table 2. Incidence and Predictors of Procedure-related Complications
Table 3. Main Predictors of Clinical Improvement During Follow-up After Percutaneous Coronary Procedure
Table 4. Main Predictors of Cumulative Total Mortality After Percutaneous Coronary Procedure
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Additional material (1)
Introduction and objectives

There is current controversy regarding the benefits of percutaneous recanalization (PCI) of chronic total coronary occlusions (CTO). Our aim was to determine acute and follow-up outcomes in our setting.


Two-year prospective registry of consecutive patients undergoing PCI of CTO in 24 centers.


A total of 1000 PCIs of CTO were performed in 952 patients. Most were symptomatic (81.5%), with chronic ischemic heart disease (59.2%). Previous recanalization attempts had been made in 15%. The mean SYNTAX score was 19.5 ± 10.6 and J-score was > 2 in 17.3%. A retrograde procedure was performed in 92 patients (9.2%). The success rate was 74.9% and was higher in patients without previous attempts (82.2% vs 75.2%; P = .001), those with a J-score ≤ 2 (80.5% vs 69.5%; P = .002), and in intravascular ultrasound-guided PCI (89.9% vs 76.2%, P = .001), which was an independent predictor of success. In contrast, severe calcification, length > 20mm, and blunt proximal cap were independent predictors of failed recanalization. The rate of procedural complications was 7.1%, including perforation (3%), myocardial infarction (1.3%), and death (0.5%). At 1-year of follow-up, 88.2% of successfully revascularized patients showed clinical improvement (vs 34.8%, P < .001), which was associated with lower mortality. At 1-year of follow-up, the mortality rate was 1.5%.


Compared with other national registries, patients in the Iberian registry undergoing PCI of a CTO showed similar complexity, success rate, and complications. Successful recanalization was strongly associated with functional improvement, which was related to lower mortality.

Chronic total occlusions
Chronic ischemic cardiomyopathy
Introducción y objetivos

El impacto de la intervención coronaria percutánea (ICP) sobre oclusiones coronarias crónicas totales (OCT) presenta controversias. Se analizan los resultados agudos y al seguimiento en nuestro entorno.


Registro prospectivo de ICP sobre OCT en 24 centros durante 2 años.


Se realizaron 1.000 ICP sobre OCT en 952 pacientes. La mayoría tenía síntomas (81,5%) y cardiopatía isquémica previa (59,2%), y hubo intentos de desobstrucción previos en un 15%. El SYNTAX anatómico fue 19,5 ± 10,6 y tenía J-score > 2 el 17,3%. El procedimiento fue retrógrado en 92 pacientes (9,2%). La tasa de éxito fue del 74,9%, mayor en aquellos sin ICP previa (el 82,2 frente al 75,2%; p = 0,001), con J-score ≤ 2 (el 80,5 frente al 69,5%; p = 0,002) y con el uso de ecografía intravascular (el 89,9 frente al 76,2%; p = 0,001), que fue predictor independiente del éxito. Por el contrario, lesiones calcificadas, > 20 mm o con muñón proximal romo lo fueron de fracaso. El 7,1% tuvo complicaciones, como perforación (3%), infarto (1,3%) o muerte (0,5%). Al año de seguimiento, el 88,2% mejoró clínicamente en caso de ICP exitosa (frente al 34,8%; p < 0,001). Dicha mejoría se asoció con menor mortalidad. La tasa de mortalidad al año fue del 1,5%.


Los pacientes del Registro Ibérico con OCT tratados con ICP presentan complejidad clínico-anatómica, tasas de éxito y complicaciones similares a los de otros registros nacionales e importante impacto de la recanalización exitosa en la mejoría funcional, que a su vez se asoció con menor mortalidad.

Palabras clave:
Oclusiones crónicas
Cardiopatía isquémica crónica
Full Text

There is current controversy in the cardiologic community regarding the benefits of percutaneous coronary intervention (PCI) in chronic total coronary occlusions (CTO).1 This has led to some skepticism when ordering these procedures because they are usually complex, take a long time, use higher radiation doses, and have a lower success rate.2,3 Although up to 30% of patients treated by coronary angiography have at least 1 CTO, PCI is currently attempted on this lesion in only ∼4% of patients in our setting.4,5 This reluctance can be explained by 2 main reasons. On the one hand, early concerns about the prognostic benefit (understood as cardiovascular mortality) have not been resolved in more recent studies,6 despite ongoing improvements in parameters, such as the ventricular function, angina grade, and arrhythmic burden of patients in multiple registries.7–11 On the other hand, the success rate at hospitals highly experienced in these interventions is not consistent with that reported in the largest real-life registries,12–15 even with better overall outcomes due to technical improvements and due to the establishment of specific programs and specially trained staff.

The aims of the Iberian registry were first to determine the current success rate for attempts to unblock CTO in our setting by specially trained operators, based on a consecutive 2-year series and second, to learn the impact on prognosis and functional capacity of both success and failure of this intervention.

METHODSCase Definition and Registry

A prospective, consecutive registry of patients who had undergone CTO angioplasty was created through the Iberian registry. A total of 32 sites in Spain and Portugal participated in this registry. A 2-year recruitment period from January 2015 to December 2016 was selected, during which 24 of the participating sites included patients (Table of the supplementary material). We defined CTO as angiographically proven anterograde flow obstruction of a coronary artery, known or suspected to have lasted > 3 months (with Thrombolysis In Myocardial Infarction [TIMI] flow = 0).1 The study included a total of 24 sites selected from around Spain with at least 1 operator experienced in CTO angioplasty who recorded all cases consecutively, independently, and without outside monitoring. An experienced operator was assumed to be any operator who had handled at least 50 chronic occlusions and who had been previously mentored in this intervention. Although this criterion represents a selection bias, the aim was to reflect current outcomes with this technique using a specific strategy. Once informed consent was obtained, data were obtained on clinical, anatomic (including specifically on occlusion), and procedure characteristics. Patients were considered to have a history of ischemic heart disease only if diagnosed before the procedure detecting the CTO to be treated. A total of 99% of the patients included were monitored during their hospital stay and at least once after discharge. A total of 37 procedures were excluded due to inclusion errors or duplicate data. The clinical assessment was performed by the attending clinical cardiologist according to Canadian Cardiovascular Society angina functional class (I to IV) and New York Heart Association dyspnea class (I to IV); clinical improvement was considered to be reduction of at least 1 grade on these scales. Additionally, quality of life was assessed by the EQ-5D Health Questionnaire and the Seattle Angina Questionnaire in a subpopulation. Each site entered the data using an online platform, complying with the requirements of the Law on Data Protection and accessible only to participating operators and registry coordinators. The registry is endorsed by the Cardiac Catheterization and Interventional Cardiology Section of the Spanish Society of Cardiology and was funded by an unconditional grant from Abbott Vascular Spain.

Statistical Methods

Data are expressed as absolute and percent frequency in the case of qualitative variables. Quantitative variables are expressed as mean ± standard deviation or median [interquartile range], depending on variable distribution. Group comparisons were analyzed by the Student t test or its nonparametric equivalent, the Mann-Whitney U-test, for continuous variables, and the chi-square test or Fisher's exact test for categorical variables. Statistical significance was defined as P < .05. Variables with P < .10 in the univariate analysis were included in a multivariate logistic regression model to determine the predictors of recanalization success, the predictors of complications, and the predictors of functional improvement. Survival curves during total mortality follow-up were estimated by the log-rank test based on success or failure of CTO recanalization. Predictors of mortality were not analyzed, in order to avoid any overadjustments due to a low incidence.

All analyses were performed using SPSS Statistics, version 24.0.

RESULTSBaseline Characteristics

A total of 1000 CTO angioplasties were performed in 952 patients over a 2-year period; 83.8% were men, and the mean age was 65.5 ± 11.3 years. Most patients had symptoms (81.5%) and a history of ischemic heart disease (59.2%), with surgical revascularization in 5.6%, percutaneous revascularization in 48.4%, and previous attempts at unblocking in 15%. The mean anatomic-based SYNTAX score was 19.5 ± 10.6 (left common trunk disease in 4.1% and more than 1 chronic occlusion in 14.8%), and 17.3% had a J-score > 2. The main clinical and anatomic characteristics are summarized in Table 1.

Table 1.

Clinical, Anatomic, Procedure, and Inpatient Characteristics and Main Predictors of Angiographic Success

CharacteristicsTotal procedures (n = 1000)Univariate analysisMultivariate analysis*
Failure (n = 192 [25.1%])  Success (n = 718 [74.9%])  P  OR (95%CI)  P 
Clinical characteristics
Men  798 (83.8)  167 (87.0)  594 (82.7)  .158     
Hypertension  647 (68.0)  139 (76.4)  472 (69.7)  .079     
Type 2 diabetes mellitus  348 (38.6)  77 (40.1)  269 (37.5)  .745     
Dyslipidemia  614 (64.5)  119 (66.1)  464 (68.3)  .570     
CKF  100 (10.5)  22 (13.1)  72 (11.5)  .570     
Creatinine, mg/dL  1.23 ± 3.64  1.13 ± 0.93  1.26 ± 4.16  .005     
Peripheral artery disease  97 (10.2)  22 (12.8)  70 (11.1)  .536     
History of IHD  564 (59.2)  123 (66.1)  418 (62.1)  .315     
History of AMI  283 (28.3)  69 (36.5)  200 (28.4)  .031     
History of PCI  461 (48.4)  109 (56.8)  332 (46.3)  .010     
History of bypass  53 (5.6)  15 (7.8)  36 (5.0)  .134     
Angina, CCS III-IV  286 (30)  55 (28.6)  219 (30.5)  .707     
Anatomic characteristics
LCT disease  39 (4.1)  10 (6.1)  28 (4.6)  .431     
3-vessel disease  181 (19.0)  37 (19.3)  139 (19.4)  .947     
Anatomic-based SYNTAX score  19.5 ± 10.6  18 [12-25]  17 [12-23]  .224     
More than 1 CTO  141 (14.8)  37 (19.3)  99 (13.8)  .135     
J-score > 2  173 (17.3)  50 (24.6)  114 (15.1)  .001     
Blunt proximal cap  449 (51.5)  126 (68.5)  323 (47.0)  < .001  0.412 (0.263-0.646)  < .001 
Branch at proximal cap  375 (48.0)  77 (45.3)  298 (48.7)  .433     
Length > 20 mm  432 (46.3)  122 (63.9)  310 (41.7)  < .001  0.606 (0.386-0.950)  .029 
Calcification  648 (68.8)  159 (80.7)  489 (65.6)  < .001  0.530 (0.302-0.931)  .027 
Tortuous vessel(s)  282 (28.1)  85 (45.4)  197 (28.5)  < .001  0.644 (0.408-1.016)  .058 
Rentrop 3  281 (28.1)  52 (26.4)  223 (29.9)  .146  1.777 (1.010-3.128)  .046 
CC2 collaterals  362 (36.2)  72 (36.5)  283 (38.0)  .291     
Procedure characteristics
Previous attempt  149 (14.9)  37 (21.3)  98 (15.4)  .068     
Retrograde approach  92 (9.2)  26 (12.9)  66 (8.8)  .082     
Contralateral injection  511 (51.2)  125 (71.4)  367 (58.4)  .002  0.646 (0.407-1.025)  .063 
Femoral access only  437 (43.7)  83 (41.1)  354 (47.7)  .002     
IVUS  116 (11.6)  11 (6.8)  97 (16.6)  .002  2.445 (1.186-5.041)  .015 
Crossboss-Stingray  9 (0.9)  5 (3.9)  4 (0.8)  .023     
Rotablator  12 (1.2)  12 (1.6)  .133     
Complications  71 (7.1)  30 (14.8)  40 (5.4)  < .001     
Coronary dissection  13 (1.3)  4 (2.0)  9 (1.2)  .492     
Coronary perforation  31 (3.1)  19 (9.4)  11 (1.5)  < .001  0.129 (0.049-0.343)  < .001 
Tamponade  10 (1.0)  6 (3.0)  4 (0.5)  .009     
Cardiogenic shock  6 (0.6)  2 (1.0)  4 (0.5)  .614     
Need for ECMO  1 (0.1)  1 (0.5)  .999     
Fluoroscopy, min  42 ± 30  54 ± 36  41 ± 32  < .001     
Contrast, mL  293 ± 162  332 ± 197  284 ± 152  .007     
Inpatient results
Type 2 AMI  13 (1.3)  3 (1.5)  10 (1.3)  .999     
Stroke  —     
CIN  3 (0.3)  1 (0.5)  2 (0.2)  .999     
Acute thrombosis  —     
Major vascular complication  5 (0.5)  1 (0.5)  4 (0.5)  .999     
Urgent bypass  —     
Inpatient death  5 (0.5)  5 (0.7)  .590     

AMI, acute myocardial infarction; CC2, collateral connection grade 2; CCS, Canadian Cardiovascular Society; 95%CI, 95% confidence interval; CIN, contrast-induced nephropathy; CKF, chronic kidney failure; CTO, chronic total occlusion; ECMO, extracorporeal membrane oxygenator; IHD, ischemic heart disease; IVUS, intravascular ultrasound; LCT, left common trunk; OR, odds ratio; PCI, percutaneous coronary intervention.

Data are expressed as No. (%), mean ± standard deviation, or median [interquartile range].


All significant variables were included in the model. Only those remaining in the last step are shown.

Procedure Characteristics

The characteristics of the procedure, as well as the predictive factors of successful recanalization and complications, are summarized in Table 1 and Table 2, respectively. The right coronary artery was most commonly affected (50.2%; 73.7% successful), followed by the anterior interventricular artery (34.3%; 83.5% successful) and circumflex artery (14.9%; 87.3% successful). The procedure was retrograde in 92 patients (9.2%) and considered as a first option in 75%.

Table 2.

Incidence and Predictors of Procedure-related Complications

Characteristics  No complications (n = 881 [93.1%])  Complications (n = 65 [6.9%])  P 
Clinical characteristics
Men  741 (84.1)  52 (80.0)  .385 
Hypertension  598 (71.9)  46 (74.2)  .695 
Type 2 diabetes mellitus  349 (39.6)  18 (27.7)  .145 
Dyslipidemia  567 (68.2)  44 (69.8)  .791 
Smoking  328 (40.7)  25 (40.3)  .948 
CKF  65 (8.5)  5 (8.2)  .154 
Creatinine, mg/dL  0.9 [0.8-1.1]  0.9 [0.8-1.0]  .465 
Peripheral artery disease  91 (11.8)  6 (9.8)  .652 
History of IHD  511 (61.7)  49 (77.8)  .011 
History of AMI  259 (29.9)  23 (37.1)  .237 
History of PCI  420 (47.7)  39 (60.0)  .056 
History of bypass  47 (5.3)  5 (7.7)  .395 
Angina, CCS III-IV  261 (29.6)  24 (36.9)  .396 
Anatomic characteristics
LCT disease  37 (5.0)  2 (3.3)  .431 
3-vessel disease  164 (18.6)  16 (24.6)  .426 
Anatomic-based SYNTAX score  17.5 [12-24]  22 [15-28]  .031 
J-score > 2  156 (16.9)  16 (22.5)  .228 
Blunt proximal cap  410 (49.5)  49 (72.1)  < .001 
Branch at proximal cap  362 (48.6)  25 (40.3)  .211 
Length > 20 mm  407 (45.1)  41 (60.3)  .016 
Calcification  621 (68.2)  51 (75.0)  .246 
Tortuous vessel(s)  271 (32.3)  23 (33.8)  .718 
Rentrop 3  258 (28.4)  20 (29.4)  .852 
CC2 collaterals  338 (37.1)  22 (32.4)  .123 
Procedure characteristics
Previous attempt  134 (16.9)  9 (17.3)  .946 
Retrograde approach  80 (8.7)  15 (21.1)  .001 
Contralateral injection  458 (60.1)  49 (73.1)  .036 
IVUS  106 (15.0)  9 (14.8)  .953 
Crossboss-Stingray  7 (1.2)  2 (3.4)  .206 
Rotablator  12 (1.3)  .999 
Fluoroscopy, min  33 [21-54]  45 [32-85]  < .001 
Contrast, mL  260 [180-353]  320 [235-417]  .013 

AMI, acute myocardial infarction; CC2, collateral connection grade 2; CCS, Canadian Cardiovascular Society; CKF, chronic kidney failure; IHD, ischemic heart disease; IVUS, intravascular ultrasound; LCT, left common trunk; PCI, percutaneous coronary intervention.

Data are expressed as No. (%), mean ± standard deviation, or median [interquartile range].

The overall success rate was 74.9%, higher in patients with no previous attempts (82.2% vs 75.2%; P = .001), in patients with J-score ≤ 2 (80.5% vs 69.5%; P = .002) and in procedures performed with intravascular ultrasound (IVUS) guidance (89.9% vs 76.2%; P < .001). In fact, the use of IVUS was the only modifiable factor that was an independent predictor of success (odds ratio [OR] = 2.445; 95% confidence interval [95%CI], 1.186-5.041; P < .015). Patients with worse kidney function and patients with complications during the procedure had lower success rates, and in particular, the presence of coronary perforations was associated with significantly fewer successful recanalizations (34.5% vs 79.9%; P < .001). The main factors described by the J-score, such as severe calcification, length > 20mm, and a blunt proximal cap, were also independent predictors of failed recanalization. Success varied from 68% to 91% among sites and was higher in the top quartile according to number of procedures (P = .056).

The procedure-related complication rate was 6.9%: coronary perforation (3%), cardiac tamponade (1%), myocardial infarction (1.3%), and death (0.5%). Complication-related factors are summarized in Table 2; independent predictors were a history of ischemic heart disease (OR = 2.230; 95%CI, 1.104-4.505; P = .025), blunt proximal cap (OR = 2.068; 95%CI, 1.088-3.934; P = .027), and retrograde access (OR = 3.527; 95%CI, 1.691-7.359; P < .001). The overall hospital mortality rate was 0.5%, and there were no significant differences according to PCI success or failure.

Clinical Results and Prognostic Impact

After a median follow-up of 365 [167-532] days, 78.3% of patients showed an improvement in New York Heart Association functional class for dyspnea or in Canadian Cardiovascular Society grade for angina. In 95% of patients with at least 2 years of follow-up who improved in the first year, the improvement persisted afterwards. In addition, a subpopulation of 183 patients showed significant improvement in the EQ-5D scale from 0.794 ± 0.115 to 0.869 ± 0.097 (P = .092) and in the Seattle Angina Questionnaire from 83.4 (75.4-90.0) to 95.1 (87.3-99.0) (P < .001). The main factors associated with functional improvement are shown in Table 3. Clinical improvement was significantly lower in the case of failed PCI (27.3% vs 92%; P < .001), as summarized in Figure 1. In addition to failed recanalization, the presence of other clinical conditions associated with functional impairment, such as a history of infarction or stroke and peripheral arterial disease, was associated with a lack of clinical improvement. Moreover, patients who experienced less clinical improvement had higher mortality (Table 4).

Table 3.

Main Predictors of Clinical Improvement During Follow-up After Percutaneous Coronary Procedure

Characteristics  No clinical improvement (n = 175 [21.7%])  Clinical improvement (n = 689 [78.3%])  P 
Clinical characteristics
Men  154 (88.0)  565 (82.0)  .058 
Hypertension  118 (71.1)  471 (72.1)  .789 
Type 2 diabetes mellitus  68 (38.8)  264 (38.3)  .389 
Dyslipidemia  106 (64.2)  447 (68.6)  .290 
Smoking  67 (40.9)  248 (39.3)  .718 
CKF  24 (15.5)  63 (10.5)  .085 
Creatinine, mg/dL  0.99 [0.8-1.21]  0.9 [0.8-1.07]  .004 
Peripheral artery disease  23 (14.8)  63 (10.4)  .094 
History of stroke  15 (9.5)  35 (5.8)  .093 
History of IHD  112 (66.7)  403 (62.2)  .284 
History of AMI  63 (36.4)  195 (29.0)  .060 
History of PCI  94 (53.7)  337 (49.0)  .264 
History of bypass  13 (7.4)  37 (5.4)  .298 
Angina, CCS III-IV  52 (29.7)  212 (30.8)  .396 
Anatomic characteristics
LCT disease  6 (4.0)  29 (4.9)  .629 
3-vessel disease  6 (3.4)  11 (1.6)  .531 
Anatomic-based SYNTAX score  16.5 [10-25]  18 [12-24]  .266 
J-score > 2  42 (24.0)  107 (15.5)  .008 
Blunt proximal cap  95 (59.7)  306 (48.4)  .011 
Branch at proximal cap  70 (47.0)  271 (47.5)  .902 
Length > 20 mm  101 (59.4)  292 (42.6)  < .001 
Calcification  135 (77.1)  469 (68.1)  .019 
Tortuous vessel(s)  72 (43.1)  185 (29.2)  .002 
Rentrop 3  48 (27.4)  195 (28.3)  .204 
CC2 collaterals  66 (37.7)  250 (36.3)  .342 
Procedure characteristics
Occlusion length, mm  30 [20-40]  20 [15-30]  < .001 
Complications  18 (10.3)  39 (5.7)  .29 
Successful revascularization  42 (24.1)  611 (93.1)  < .001 

AMI, acute myocardial infarction; CC2, collateral connection grade 2; CCS, Canadian Cardiovascular Society; CKF, chronic kidney failure; IHD, ischemic heart disease; LCT, left common trunk; PCI, percutaneous coronary intervention.

Data are expressed as No. (%), mean ± standard deviation, or median [interquartile range].

Figure 1.

Clinical progress during long-term follow-up of patients treated by revascularization of chronic coronary occlusion; total population and according to recanalization success or failure.

Table 4.

Main Predictors of Cumulative Total Mortality After Percutaneous Coronary Procedure

Characteristics  Survival during follow-up (n = 925 [97.2%])  Death during follow-up (n = 27 [2.8%])  P 
Clinical characteristics
Men  776 (83.9)  22 (81.5)  .790 
Hypertension  630 (72.0)  17 (68.0)  .661 
Type 2 diabetes mellitus  357 (38.6)  11 (40.7)  .821 
Dyslipidemia  601 (68.6)  13 (54.2)  .134 
Smoking  346 (40.7)  9 (39.1)  .879 
CKF  95 (11.8)  5 (21.7)  .182 
Creatinine, mg/dL  0.9 [0.76-1.09]  1.07 [0.75-1.29]  .139 
Peripheral artery disease  92 (11.3)  5 (20.0)  .196 
History of IHD  546 (62.8)  18 (66.7)  .679 
History of AMI  272 (30.0)  11 (42.3)  .178 
History of PCI  451 (48.8)  10 (37.0)  .228 
History of bypass  50 (5.4)  3 (11.1)  .186 
Angina, CCS III-IV  274 (29.6)  12 (44.4)  .098 
Anatomic characteristics
LCT disease  38 (4.9)  1 (4.5)  .999 
3-vessel disease  172 (18.6)  9 (33.3)  .054 
Anatomic-based SYNTAX score  15 [8-22]  16 [5-25]  .688 
J-score > 2  162 (17.5)  4 (14.8)  .999 
Blunt proximal cap  426 (50.4)  16 (64.0)  .179 
Branch at proximal cap  365 (47.7)  12 (54.5)  .527 
Length > 20 mm  424 (46.2)  12 (44.4)  .854 
Calcification  630 (68.1)  20 (74.1)  .511 
Tortuous vessel(s)  281 (32.8)  3 (12.0)  .029 
Rentrop 3  264 (28.5)  7 (25.9)  .767 
CC2 collaterals  341 (36.9)  12 (44.4)  .416 
Procedure characteristics
Complications  63 (6.9)  2 (7.4)  .708 
Successful revascularization  697 (79.1)  19 (70.4)  .273 
Clinical course
No changes  170 (18.8)  11 (44.0)  < .001
Functional impairment  13 (1.4)  3 (12.0) 
Functional improvement  719 (79.7)  11 (44.0) 

AMI, acute myocardial infarction; CC2, collateral connection grade 2; CCS, Canadian Cardiovascular Society; CKF, chronic kidney failure; IHD, ischemic heart disease; LCT, left common trunk; PCI, percutaneous coronary intervention.

Data are expressed as No. (%) or median [interquartile range].

Of the 877 patients who completed 1-year follow-up (92.1% of total), 14 (1.5%) died, with no significant differences according to recanalization outcome. One-year mortality curves showed some divergence in favor of patients with successful recanalization. In patients with 3 years of follow-up, the mortality rate was higher in the case of failed recanalization (28.7% vs 18.9%), although the difference was not statistically significant (P = .153) (Figure 2). The main determinants of mortality during follow-up are summarized in Table 4.

Figure 2.

Survival curves based on successful or failed treatment of chronic coronary occlusion.


The Iberian registry on chronic occlusions is an initial contemporary effort to prospectively record the results of specific CTO recanalization programs recently implemented at many Spanish hospitals by operators trained in this technique. Following these criteria, a total of 952 patients from 24 sites were recruited, which accounts for 15.8% of all CTO treated during the same period at the 80 public sites with data published in the Spanish Cardiac Catheterization and Coronary Intervention Registries.4,5 The main findings were: a) evidence of similar success rates to those seen in other national and international registries and, consistent with them, the existence of a noticeable interhospital variability, with success rates of 68% to 91%, which are higher in the top quartile according to the number of procedures (Figure 3); b) although this registry does not have an arm with medical therapy only, it does show that patients referred for percutaneous recanalization who finally required medical therapy due to a failed procedure not only had worse functional status, but also had higher absolute mortality after the first year of follow-up, although this was not statistically significant, and c) although the validation of some traits of complexity (summarized in the J-score) was useful to predict failed recanalization, this registry identified modifiable factors that had an adverse impact on outcomes, such as low use of IVUS or low success rates by retrograde approach, which indicate reference points for future studies and targets where work can be done to improve these outcomes.

Figure 3.

Success rate for percutaneous recanalization procedures in chronic coronary occlusions at the various participating sites, divided into quartiles according to the number of patients treated at each site. Abbreviation: Pt., patients.

Baseline Characteristics and Indication of Recanalization Procedure

Patients with CTO were characterized by a high incidence of multiple cardiovascular risk factors and injury to other target organs, as well as multivessel disease, with a mean anatomic-based SYNTAX score of 19.5 ± 10.6, and complex lesions with J-score > 2 in 17.3% of patients. This is consistent with the data of the Canadian Multicenter CTO Registry7 and other similar registries7,16–19 indicating that isolated CTO are only present in 47% of patients. It is common for surgery to be ruled out in patients with single-vessel or multivessel disease but other comorbidities or poor distal bed visualization. In this situation, medical therapy was the first alternative for decades, but a significant percentage of patients still show evidence of ischemia or relevant symptoms8–11; in particular, up to 30% of patients included in the Iberian registry had Canadian Cardiovascular Society functional class III or IV angina. These data, along with the poor progress of patients with failed vs successful recanalization, appear to show that the indications of PCI for CTO are adequate in our setting.

Technical Aspects and Interhospital Variability

Imaging techniques such as IVUS or computed tomography are not commonly used in our setting (∼11%), even though they could provide diagnostic and therapeutic benefits to patients with limited angiographic visualization. Some studies report that IVUS is mainly used in more complex CTO and that it increases the success rate. This technique was used in more than 40% of patients in the Japanese Multicenter CTO Registry20 and the Multicenter Korean CTO Registry.21 However, the European Registry of Chronic Total Occlusion10,22 had lower rates (2.9% in all; 9.2% of retrograde) and indicate, like the Iberian registry, that it is not used as often by less expert operators. Habara et al.23 has already analyzed the impact of operator experience, showing that IVUS guidance to cross the guidewire has a clear learning curve affecting the need for support from expert operators for this technique to have a positive impact.24 This could also be said of the retrograde approach which, in our series, was a predictor of complications and is another modifiable factor that could increase the success rate. The use of 2 catheters (1 for contralateral injection) is not an independent predictor of success, which might indicate that this strategy is only used in the most complex cases and not in all situations in which it may be beneficial20,21; this could also explain why the rate of successful recanalizations is higher for PCI on the circumflex artery, even though previous series have always reported lower rates.20–23 In fact, less than 15% of attempts were performed on this artery, showing that a nonnegligible percentage of patients who might benefit from percutaneous recanalization by specific techniques are using medical therapy as the first and only option. On the other hand, the fact that eventually patients with failed attempts have more complications could indicate another potentially modifiable point that might increase the success rate and identify patients at risk of complications, making it possible to halt the procedure or to change how it is being done before complications occur.

Prognostic Impact

This study was not intended to demonstrate impact on mortality, as this is a controversial aspect that requires well-designed studies with a control group, although such studies are often a matter of debate in the field of CTO.25 However, there was a low rate of complications, with no cases of urgent heart surgery and with a periprocedure mortality of only 0.5%. In addition, patients clearly experienced functional benefit, which was also associated with lower mortality during follow-up (P < .001) (Table 4), confirming that there are undeniable benefits to patients treated by CTO recanalization in cases with a clear indication. Although some studies, such as SYNTAX26 or the study by Banerjee et al.,18 have compared percutaneous recanalization in CTO vs surgery with slightly more favorable results in the percutaneous recanalization arm, these cohorts are not recent and also include patients with multivessel disease, without considering that the surgical outcomes were clearly worse when saphenous vs mammary grafts were used. This explains the minimal use of surgery in patients with single-vessel disease, particular in those with occlusion of the right coronary artery, which usually cannot be revascularized with mammary graft and is actually the artery most commonly affected by CTO.27–29 The Iberian registry indicates that, although not obvious during the first year after the intervention, mortality during longer term follow-up could be significantly reduced and also indicates that percutaneous recanalization of CTO in patients with no surgical indication (due to high risk or low SYNTAX score) is an alternative to consider in our setting, particularly in patients with symptoms and ischemia no longer alleviated by medical treatment.


The main limitations of this study is that, although it was performed prospectively and systematically, the data are informative and not monitored and there is no centralized angiographic analysis. In fact, the patients included are those selected by each hospital to undergo PCI, which could lead to heterogeneity between the clinical indications. This also explains why ischemia test data are not recorded, as the indication was defined at each hospital and there were no restrictions on indication in terms of inclusion criteria. Nevertheless, the study helps provide an accurate picture of clinical practice in our setting. Additionally, complications could be underestimated because the registry did not include a systematic record of electrocardiograms and sequential measurements of necrosis markers. It is true that a strict definition of infarction or perforation may increase the overall rate of complications when compared with other, less rigorous registries. Consequently, it should be taken into account that not all complications involve the same risk burden for the patient, as seen by the fact that no patients died during the procedure or required urgent recanalization surgery. Last, the data on clinical improvement were based on dyspnea status (New York Heart Association) and angina status (Canadian Cardiovascular Society), but there was no routine use of specific questionnaires or other objective examinations.


The Iberian registry is the first national registry on interventional cardiology in CTO and includes a large number of hospitals and patients. These patients had similar clinical and anatomic complexity to patients in other national registries, with comparable success and complication rates and with successful recanalization having a major impact on functional improvement.


This study was funded by an unconditional grant from Abbott Vascular Spain.


J.M. de la Torre Hernández received unconditional research grants from Boston and Abbott Vascular. J. Núñez Villota has given lectures sponsored by Abbott Vascular. All other authors declare no conflict of interests.


  • There is controversy in the cardiologic community regarding the outcome of percutaneous recanalization procedures in CTO. Success rates at hospitals highly experienced in these surgeries are not consistent with those obtained in larger clinical practice registries. In fact, the current results of this intervention in our setting are unknown.


  • The Iberian registry is the first contemporary interventional cardiology registry on CTO in our setting. The mean rate of successful recanalization was 74.9%, similar to that of other national registries. The use of IVUS was an independent predictor of success, whereas a high J-score and retrograde approach were independent predictors of failure. Successful recanalization had a major impact on functional improvement, which was associated with lower mortality during follow-up.

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