Relationship of cardiac allograft size and pulmonary vascular resistance to long-term cardiopulmonary function

The purpose of this study was to evaluate the long-term cardiopulmonary function of heart transplant patients who received disproportionately sized allografts for varying levels of pulmonary vascular resistance. Resting hemodynamics and oxygen uptake during exercise were recorded at 1 year after transplantation in 52 patients. No differences in resting heart rate, cardiac output, stroke volume, peak oxygen uptake during exercise, and exercise duration were found in recipients of undersized hearts (donor:recipient weight ratio [D:R] < 0.75), sized-matched hearts (D:R = 0.75 to 1.25), and oversized (D:R > 1.25) hearts. In a further analysis according to preoperative pulmonary vascular resistance, resting cardiac output (5.8 +/- 1.3 L/min) was normal, and peak exercise oxygen uptake (22.7 +/- 8.0 ml/kg/min) was mildly decreased in recipients of size-matched allografts with a pulmonary vascular resistance of less than 3 Wood units (size-matched hearts, with mild or no pulmonary vascular resistance). Of patients with moderate pulmonary hypertension (pulmonary vascular resistance > or = 3 Wood units), resting cardiac output was normal (5.1 +/- 0.6 L/min) in recipients of oversized hearts and was reduced (4.7 +/- 1.0 L/min) in recipients of sized-matched hearts (p < 0.05 versus recipients of size-matched hearts with pulmonary vascular resistance less than 3 Wood units).(ABSTRACT TRUNCATED AT 250 WORDS)