The term refractory angina (RA) refers to a clinical picture of chronic angina-like chest pain, lasting for ≥ 3 months and is associated with reversible ischemia that persists despite optimal medical treatment and current percutaneous and surgical revascularization.1 Coronary sinus reducers (CSR) have proven to be effective in reducing symptoms in patients with RA,2 although experience with these devices and available evidence remain scarce.3,4 The aim of the present study was to describe the safety and efficacy of CRSs during an initial experience in Spain.

We conducted an observational retrospective multicenter registry of consecutive patients with RA and CSR implants in Spain. The protocol was approved by a central reference ethics committee, which waived informed consent because the data were guaranteed to be anonymous. The primary efficacy endpoint was change in functional class according to the Canadian Cardiac Society classification (FC-CCS) and the safety endpoint was procedure-related complications.

The CSRs were implanted in 48 patients with RA who could not undergo surgical or percutaneous revascularization. Implantation was considered suboptimal in 1 patient because, during follow-up, we observed device shift toward the pulmonary artery, which was asymptomatic (angiographic finding). Table 1 shows the baseline characteristics of the patients, all of whom had documented ischemia in the left coronary territory. One patient died before completing the 6-month follow-up due to causes unrelated to the intervention, and so no follow-up data are available for this patient. At 6 months postimplantation, FC-CCS class improved in 40 patients (85%), and by ≥ 2 classes (P<.001) in 22 (47%) patients (figure 1). The baseline data of the patients show that the severity of angina was higher than that described in previous studies: 90% of our patients were in FC-CCS 3 or 4 before implantation and the patients were taking a mean of 3.8±1.3 antianginal drugs at baseline.

Figure 1.

Change in angina burden (A) and angina functional class (B) at 6 months postintervention. No 6-month follow-up data for 1 patient. CCS, Canadian Cardiology Society.

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The greater severity of angina in our patients could explain the responses observed, which were significantly superior to those found in the COSIRA study2 and the RESOURCE and REDUCER-I registries.3,4Figure 1B shows the change in FC-CCS at 6 months postimplantation.

Regarding complications, there was bruising at the puncture site in 2 patients (4.2%), although they did not require transfusion or specific treatment. In 1 patient (2.1%), there was minor coronary sinus dissection, which was documented on angiography and managed without specific treatment. There were no other major implant- or device-related complications during intervention. Regarding incidents, there was device shift in 2 patients during implantation. The devices were recovered without complications through femoral venous access and a second device was successfully implanted in both patients.5

In summary, our initial experience with CSRs in Spain for the treatment of patients with RA has been favorable. Most of the patients experienced symptom improvement without any serious intervention- or device-related complications being reported.