Reduced incidence of hypertension after heterotopic cardiac transplantation compared with orthotopic cardiac transplantation: evidence that excision of the native heart contributes to post-transplant hypertension.

OBJECTIVES

This study was designed to test the hypothesis that heterotopic heart transplant (HHT) patients have lower blood pressure than orthotopic cardiac transplant (OCT) patients because their native heart is involved in blood pressure homeostasis.

BACKGROUND

Hypertension occurs more frequently after OCT than after liver or lung transplantation, suggesting that transplantation of the heart itself contributes to post-transplant hypertension.

METHODS

Blood pressure and related measurements in 233 OCT and 38 HHT patients were studied retrospectively post-transplant.

RESULTS

Systolic blood pressure (SBP) was persistently lower among HHT patients (means 121 vs. 137, 126 vs. 137, 125 vs. 139, and 128 vs. 143 mm Hg at month 3 and years 1, 3, and 5 respectively, p < 0.005). Left ventricular and aortic systolic pressures were also lower (130 vs. 143 mm Hg, p = 0.01 and 129 vs. 142 mm Hg, p = 0.01). Multivariable analysis with age, gender, body mass index, creatinine, steroids, cyclosporine, use of antihypertensive medication, donor left ventricular ejection fraction, donor weight, and type of transplant as covariables showed HHT to be independently associated with a lower SBP at each time point (beta-coefficients -16.2, -12.1, -13.3, and -14.2 mm Hg, p < 0.01). The adjusted hazard ratio for the development of systolic hypertension among HHT compared with OCT patients was 0.59 (95% confidence interval 0.39 to 0.91, p = 0.017).

CONCLUSIONS

Heterotopic heart transplant patients had lower SBP than OCT patients, consistent with the hypothesis that the native heart continues to contribute to blood pressure homeostasis.