Purpose: Limited options are available to improve the functional class of patients awaiting cardiac transplantation. We assessed the effect of carvedilol on New York Heart Association (NYHA) class, heart rate (HR), blood pressure (BP), jugular venous pressure (JVP), electrolytes and renal function in patients with markedly decreased left ventricular (LV) function referred for cardiac transplantation assessment.
Methods: Sixty-one patients (age = 52 +/- 12 yr, EF = 23 +/- 7%, VO2 max = 16 +/- 5 mL/kg/min) referred to the cardiac transplant clinic were reviewed before and after the addition of carvedilol (starting dose 3.125 mg twice daily to target dose of 25 mg twice daily) to usual heart-failure therapy. Over a 1-yr period, at each visit prior to initiation, at baseline initiation visit and at each follow-up visit, NYHA class, BP, HR, JVP, electrolytes, and renal function were obtained. Statistical analysis was performed using random effects regression approach. A multiple logistic regression analysis was performed on 52/61 patients to determine possible associations between NYHA improvement and the following patient characteristics: sex, etiology of cardiomyopathy, initial NYHA class, and dose of carvedilol.
Results: Three patients died (2 after stopping carvedilol) and 3 were transplanted. Median follow-up was 100 d. Sixteen patients reached the target dose after a mean of 137 d (2.75 visits). Estimated time-to-target dose is 8 months (5.6 visits). BP tended to increase (p = 0.07 for change in trend) with no change in JVP, electrolytes or renal function. HR decreased 6 +/- 3 b.p.m. (p = 0.03). Of 14 patients NYHA class I/II at baseline, none were class III/IV at last follow-up visit. Of 47 patients NYHA class III/IV at baseline, 25 were class I/II, and 22 were class III/IV at last follow-up (p < 0.001). Multiple logistic regression analysis did not demonstrate any factor predictive of subsequent NYHA class improvement.
Conclusions: Despite less than target doses in most patients, a favorable effect of carvedilol on functional class in patients with severe congestive heart failure (CHF) referred for transplant was observed. Those with good functional status remained stable and those with poor functional status improved or remained stable. No baseline patient characteristic predicted improvement. The shortage of donor organ requires optimal use of medical regimens which may improve functional class while awaiting transplantation and which may delay the necessity for heart transplantation. Therefore, addition of carvedilol to usual medical therapy may be beneficial even in patients with severe LV dysfunction and poor NYHA classification.