The number of implantable cardioverter-defibrillator (ICD) interventions has progressively increased in recent years due to the proven efficacy in preventing sudden death and expanded indications.1–4 Because of the high cost of these devices, strategies are needed to reduce implantation-associated costs.5 Traditionally, ICDs have been implanted in an inpatient setting, mainly to monitor acute implant-related complications.6 The main objective of the present study was to evaluate the safety of outpatient ICD implantations. A secondary analysis evaluated predictive variables for the development of complications and the cost reduction achieved from performing implantations without hospitalization.

During the study period, 401 ICD implantations were performed, 232 (58%) outpatient and 169 (42%) inpatient procedures (Figure 1). Of the inpatients, 91 had been admitted in a scheduled manner for the implant and 78 had been admitted for another cause (generally for ventricular tachycardia that prompted the implantation). The proportion of outpatient implantations significantly increased each year from the opening of the day hospital in 2007, with only 10% of patients hospitalized when undergoing ICD implantation in 2012 (Figure 2).

Figure 1.

Distribution of ICD implantations by the procedure type (outpatient or inpatient setting) and the need for hospitalization in outpatients. ICD, implantable cardioverter-defibrillator.

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Figure 2.

Time course comparing the percentage of outpatient and inpatient implantations between 2007 and 2012. A significant progressive increase is seen in the percentage of outpatient implantations, with a corresponding decrease of inpatient implantations (P < .001).

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Population characteristics are shown in Table 1, as well as a comparison between outpatients and inpatients. The only significant differences between the 2 groups were that outpatients had lower left ventricular ejection fraction and a higher proportion of generator replacements and indications for primary prevention. The mean hospital stay of the inpatients was 3.9 (SD, 4.1) days, vs 1.87 [SD, 4.3] days for those whose implantation was scheduled.

Of the 232 outpatients, only 21 (9%) had to be hospitalized (Figure 1). The reasons for hospitalization were the following: pocket hematoma in 2 patients, pneumothorax in 1, logistic or social reasons in 3, transient ischemic attack in 1, acute pulmonary edema in 1, and decision of the treating physician (without immediate observed complication) in 13. All of these patients were discharged within 1 and 6 days after the implantation and without long-time consequences. There were no statistically significant differences between these patients and those directly discharged.

There were 23 ICD-related complications (5.7%), without significant differences between the outpatient and inpatient groups in the rate of complications (Table 2). Neither were there differences in the percentage of complications between outpatients and those inpatients whose implantation was elective (6.0% vs 5.5%; P = .853). No deaths were associated with the procedure. There were 10 wound hematomas, but only 1 patient required a blood transfusion. Two patients showed symptoms compatible with stroke (one had a history of atrial fibrillation and one had an indication for oral anticoagulation). Complete remission of symptoms occurred in less than 24hours in both patients. The only patient requiring lead relocation was in the inpatient group. Analysis of the relationship between variables (as indicated in “Methods”) and the presence of complications is shown in Tables 3 and 4 (univariate) and (multivariate). The only factor related to complications was treatment with oral anticoagulants.

In the cost analysis, the mean cost in 2010 (excluding electrophysiology room costs and the price of the device) was €122 (SD, €148) for each implantation performed in the day hospital and €857 (SD, €412) for elective implantations with hospitalization (SD, €452 [€289] per day of hospitalization). Thus, each implantation performed in an outpatient setting saved approximately €735.

The usual approach for ICD implantation is to admit the patient in order to identify possible complications.6 Given the growing number of implants placed in recent years and because the cost-benefit of the devices has been disputed in some studies,7,8 cost-reducing strategies are necessary. In our experience, outpatient implantation of ICDs is safe. Because this safety also has been noted by physicians prescribing the implant, the number of outpatient procedures has progressively increased to represent approximately 90% of all implantations (Figure 2).

The characteristics of the study population are similar to those of other registries.1 Most implants were prescribed for primary prevention, and ischemia was the most common underlying heart disease. Secondary prevention was more common in the inpatient setting because the implantation often occurred after hospitalization for an arrhythmic episode. On the other hand, the left ventricular ejection fraction was lower in the outpatient group because most implantations in this group were for primary prevention, which generally requires a lower left ventricular ejection fraction.

The published incidence of complications after ICD implantation varies according to the type of complication included in the analysis. In our series, the incidence (5.7%) was similar to that described in other patient series.9,10 Various studies have reported the safety of the outpatient implantation of pacemakers.11–13 The evidence is scarcer for ICDs. In a prospective study of 71 patients randomized to same-day discharge or hospitalization for 24hours, there were no differences between the groups in the incidence of complications.14 However, that study comprised a selected low-risk population (with exclusion of subclavian puncture implantations, pacemaker dependency, and oral anticoagulant indications). Our series comprised a less selected population but there were still no differences in the incidence of complications between the outpatient and inpatient groups, despite including higher-risk patients.

In another recent study with a design and number of patients similar to ours (although only concerning implantations for primary prevention), Darda et al15 assessed the safety of outpatient implantations in a group of 198 patients discharged the same day, reporting an incidence of complications of 3% (without observing differences from a group of similar patients hospitalized for implantation). The authors commented that implantation-related complications either manifest in the short observation period afterward or appear much later, indicating that hospitalization fails to provide any relevant benefit. The incidence of pocket hematoma in that study was almost identical to that of our study (2.8% vs 2.6%, respectively). The incidence of device infection of 1.3% in our group of outpatients is also similar to that described elsewhere16,17 and was lower than that of the inpatients (1.8%). The incidence of infection may be reduced because the patients avoid the hospital environment and exposure to nosocomial gems following the implantation.

Due to earlier mobilization in those discharged on the day of the implantation, another possible complication is lead dislodgement, but in our series and 2 other studies,14,15 there was no increase in the need for lead relocation. Indeed, Choudhuri et al14 found no differences between outpatients and inpatients when using remote monitoring of the lead parameters. A rate of complications of only 1.8% was shown in the results of a recently published registry of data from the National Cardiovascular Data Registry (NCDR) containing more than 200 000 ICD implants in the United States.18 However, the authors themselves recognized that these results underestimated the true rate of complications, precluding a comparison with our results. First, unlike in our study, they only recorded inhospital complications, omitting those occurring after discharge (eg, notably, they did not include a single case of endocarditis). Moreover, the data collection method used limited the collection of information on complications, compared with the complete patient medical history used in our study. Thus, as already mentioned, their rate of hematomas of 0.3% is much lower than that seen in most series (surely indicating that the registry only recorded the most serious complications).

The only predictor of complications was treatment with oral anticoagulants, as in the series of Darda et al.15 In the present study, anticoagulant therapy was terminated and heparin was used as bridging therapy. This management strategy for patients with chronic anticoagulation has been related to increased complications from inpatient pacemaker implantations, compared with maintaining oral anticoagulation.19–21 Maintenance of oral anticoagulants could reduce adverse events after outpatient ICD implantation, but this hypothesis remains to be studied. Another alternative for possible study is whether use of the new oral anticoagulants modifies the presence of complications following cardiac device implantation. Regardless, patients with oral anticoagulant indication appear to be an at-risk population and should thus be handled with care.

Finally, given the growing number of implants and the current economic situation, there is a need for strategies that optimize health care resources. In our center, each implantation cost approximately €735 euros more with elective hospitalization in 2010. Extrapolation of that cost difference to the 232 outpatient implantations in our center that year represents a total saving of €170 520. Thus, outpatient ICD implantation appears to be a safe and promising strategy for reducing the costs associated with postimplantation hospitalization. The technique is also constantly being made simpler and cheaper: the first epicardial ICD implants were performed under surgery, but most implants are currently performed in electrophysiology rooms1 and without the need for defibrillation threshold testing.22 Further improvements have been obtained from strategies already in use, such as remote monitoring23,24 and subcutaneous defibrillators.25,26

Outpatient ICD implantation reduces implant-related costs without increasing the rate of complications. The only predictor of complications is oral anticoagulant therapy, indicating a need for optimized management of these patients.

None declared.