Relief of drug refractory angina by biventricular pacing in heart failure

Abstract

Since cardiac resynchronization therapy (CRT) improves LV function at the cost of low energetic expenditure, the authors hypothesized that it may increase the threshold of drug refractory angina in selected patients with CHF and CAD who are not amenable to myocardial revascularization. From October 1999 to April 2002, 75 patients with CHF and CAD were treated with CRT. Drug refractory angina occurred nearly daily in 8 of the 75 patients. The mean age of these eight men was 71 years, mean NYHA functional Class 3.4 ± 0.5, mean QRS duration (QRSd) 168 ± 20 ms, and mean left ventricular ejection fraction (LVEF) 0.29 ± 0.4. Diffuse CAD not amenable to myocardial revascularization was confirmed on angiography. At baseline, no patient was able to complete a 6-minute walk test because of angina. In the 6 months before CRT, the mean number of hospitalizations per patient for management of CHF or angina was 3.1 ± 0.3. All patients underwent successful CRT. Mean QRSd decreased to 141 ± 16 ms (P = 0.01 vs baseline). After 9 ± 6.1 months, LVEF increased to 0.317 ± 0.028 (P = 0.03 vs baseline), while the NYHA class decreased to 2.6 ± 0.5 (P = 0.02 vs baseline). All patients also experienced a marked decrease in angina episodes, from a mean of 8.3 ± 11.6 to 0.6 ± 1.3 episodes/week (P < 0.05), and completed a 6-minute walk test, covering a mean distance of 337 ± 68 m (vs 237 ± 136 m at baseline, P = 0.007). No further hospitalization was necessary. The beneficial effects of CRT on overall cardiac function may include a better control of angina in severely symptomatic patients.