Usefulness of implantable cardioverter-defibrillators in refractory variant angina pectoris complicated by ventricular fibrillation in patients with angiographically normal coronary arteries

Abstract

V angina pectoris is characterized by anginal symptoms at rest and transient ST elevation on the electrocardiogram due to coronary artery spasm. Ventricular arrhythmia is a well-recognized complication of this type of angina. Although calcium antagonists have been shown to be effective in preventing coronary spasm–induced ventricular arrhythmia in most patients with variant angina pectoris and normal coronary arteries, some may remain refractory. Implantable cardioverter-defibrillators (ICDs) have become a proven modality for patients at high risk of life-threatening ventricular arrhythmias. In the present study we analyzed the clinical course of 8 patients with refractory variant angina pectoris complicated by ventricular fibrillation (VF) who had normal coronary arteries on angiography. We evaluated the efficacy of the ICD in preventing sudden death in this group. • • • The study group consisted of 8 patients encountered in our own clinical practice and at additional hospitals solicited through a multicenter survey. Their medical records were reviewed. All patients fulfilled the following predefined criteria: (1) typical chest pain at rest associated with transient ST-segment elevations not present on the baseline electrocardiogram and disappearing with relief of pain; (2) documented VF immediately after the ischemic episode; (3) survival of the index episode of VF; (4) angiographically normal coronary arteries defined as patent arteries with no irregularities; (5) angiographic evidence of coronary spasm defined as transient narrowing of arterial lumen or recurrent episodes of electrocardiographically documented ischemia especially if occurring in different coronary territories; and (6) recurrent angina despite medical therapy. All patients were followed at the cardiology outpatient clinic. Patients who underwent ICD implantation were also followed at the arrhythmia clinic. Demographic and clinical data of the studied patients are outlined in Table 1. No patient had organic heart disease or any other condition known to be associated with sudden cardiac death. Seven patients were men. All patients initially presented with ischemic chest pain and transient ST elevation on the electrocardiogram. The electrocardiogram normalized in all patients after myocardial ischemia, without evidence of myocardial infarction on serial electrocardiograms. After the ischemic event, creatine kinase elevation (range 520 to 5,000 U/L [upper normal limit, 200]) was observed in 4 patients. Creatine kinase-MB fraction was within normal range. All patients had good left ventricular function, although 2 patients had reversible left ventricular dysfunction documented on serial echocardiograms. In all patients, VF followed the ischemic episode and required direct-current shock as treatment. Three patients required prolonged cardiopulmonary resuscitation. Coronary angiography demonstrated normal coronary arteries in all patients. Spontaneous coronary spasm was documented in 5 patients (Table 1). Four patients had a history of angina preceding the index event. During a mean follow up of 3.5 3.2 years (range 0.5 to 10, median 2.8), all but 1 patient had recurrent episodes of angina. All patients were discharged from the hospital on calcium antagonists at maximum tolerated doses (Table 1). Although treatment with calcium antagonists seemed to reduce the frequency and intensity of recurrent angina in most patients, it did not prevent its occurrence. Ventricular arrhythmia reoccurred after discharge from the hospital in all patients. Median time to the first arrhythmia recurrence was 15 months (range 2 to 112). An ICD was subsequently implanted in 7 patients. All devices were capable of storing electrograms. Before ICD implantation, 4 patients had another episode of VF, 1 patient had an episode of complete atrioventricular block, and 1 patient had multiple long runs of nonsustained ventricular tachycardia after the ischemic events. After ICD implantation, 4 patients received appropriate ICD shocks for ventricular tachycardia/VF as judged on the basis of stored electrographic analysis (Figure 1). Of these 4, 2 patients experienced 2 episodes of VF each. One patient died 19 months after ICD From the Heart Institute, Hillel Yaffe Medical Center, Hadera; Department of Cardiology, Rabin Medical Center, Petah Tikva; Department of Cardiology, Meir General Hospital, Kfar Saba; Department of Cardiology, Kaplan Medical Center, Rehovot; Golda Medical Center, Petah Tikva; and Soroka Medical Center, Beer Sheba, Israel. Dr. Meisel’s address is: Heart Institute, Hillel Yaffe Medical Center, Hadera 38100, Israel. E-mail: meisel@netvision.net.il. Manuscript received October 18, 2001; revised manuscript received and accepted January 24, 2002.