VASCULAR REMODELING IN INTRAMYOCARDIAL RESISTANCE VESSELS IN HYPERTENSIVE HUMAN CARDIAC TRANSPLANT RECIPIENTS

Objective-Cardiac transplant recipients often develop hypertension as a side effect of immunosuppressive treatment. The aim of this study wa s to use the serial endomyocardial biopsies taken to monitor rejection to study the early and sequential arterial changes in human myocardia l resistance arteries as hypertension develops. Methods-At least 14 bi opsies were studied hem each of 23 patients, divided into a normotensi ve group (12 patients with a diastolic pressure never greater than 90 mm Hg) and a hypertensive group (11 patients with more than 10% of dia stolic pressure measurements above 100 mm Hg). Morphometric analysis o f between 30 and 50 arteries and arterioles in two widely separated hi stological levels from each biopsy was undertaken using an Optomax ima ge analyser. Results-There was a correlation between blood pressure, p articularly diastolic pressure, and rate of medial thickening of intra myocardial coronary resistance arteries and arterioles (P = 0.0025). T here was also a correlation between serum cyclosporin A concentrations and mean artery wall thickness (P = 0.003). Conclusions-Hypertension and cyclosporin A treatment are associated with significant wall thick ening of intramyocardial resistance vessels in cardiac allograft recip ients. These changes may be functionally and clinically important.