Restrictive hemodynamic patterns after cardiac transplantation: Relationship to histologic signs of rejection

Abstract

Hemodynamic and echocardiographic data from 33 consecutive patients undergoing cardiac transplantation were correlated with endomyocardial biopsy results to determine whether reversible restrictive hemodynamics accompany histologic evidence of transplant rejection. During the study period 251 biopsy specimens were obtained during periods of no histologic evidence of transplant rejection and 52 episodes of mild, 20 episodes of moderate, and one episode of severe rejection. Right atrial mean pressure increased significantly during episodes of moderate transplant rejection (9.9 ± 6.2 mm Hg, p < 0.001) compared with pressures obtained during periods when there was no evidence of rejection (4.6 ± 3.2 mm Hg), mild rejection (5.8 ± 3.9 mm Hg), or resolving rejection (4.3 ± 3.4 mm Hg). Y descent was elevated during moderate rejection (9.6 ± 4.2 mm Hg, p < 0.001) compared with pressures during episodes of no rejection (5.6 ± 2.5 mm Hg), mild rejection (6.6 ± 2.7 mm Hg), and resolving rejection (5.8 ± 3.1 mm Hg) and showed a wave morphology consistent with a restrictive hemodynamic pattern. Pulmonary capillary wedge pressure was increased during moderate rejection (14.4 ± 6.4 mm Hg) when compared with pressures obtained during episodes of no rejection (10.2 ± 5.8 mm Hg) or resolving rejection (10.2 ± 5.4 mm Hg) ( p < 0.02). Sensitivity for a right atrial mean pressure of 11 mm Hg indicating moderate rejection was 41% with a specificity of 96%. Sensitivity for Y descent (≥ 10 mm Hg) was 52% and specificity was 94%. In patients without rejection right atrial mean pressure and Y descent showed a decrease over the initial 8 week posttransplant period, but the significant increases in right atrial mean pressure and Y descent during moderate rejection remained. From 27 patients 148 echocardiograms were evaluated for chamber size and wall thickness and alteration of left ventricular systolic function. Fractional shortening and fractional area change were measured. Doppler echocardiograms from 20 patients were evaluated for pressure half-time, deceleration time, peak deceleration time, and peak diastolic velocity of the mitral valve. No two-dimensional or Doppler echocardiographic parameters correlated with transplant rejection status. Histologic evidence of moderate transplant rejection is associated with a reversible increase in right atrial mean pressure and Y descent indicating restrictive hemodynamics, with a high specificity but a low sensitivity. Transplanted hearts exhibit normal hemodynamics 9 weeks after transplantation. There are no two-dimensional echocardiographic signs that predict rejection status, and a single Doppler echocardiographic analysis does not differentiate between patients with or without transplant rejection.