Background: The clinical utility of intimal hyperplasia detected by intravascular ultrasonography in predicting cardiac events in heart transplant recipients with cardiac allograft vasculopathy has not been previously investigated.
Methods: Intravascular ultrasonographic examination of 74 consecutive heart transplant recipients, including 62 men and 12 women with a mean age of 51 +/- 10 years (range 22 to 68 years), was performed at the time of annual angiography. Two groups of study patients were identified: group I consisted of patients with minimal, mild, or moderate intimal thickness by intravascular ultrasonography, whereas group II patients had severe intimal thickness.
Results: Patient characteristics were similar in both groups except for higher serum triglycerides (220 +/- 95 versus 165 +/- 79 mg/dl), more advanced donor age (28 +/- 11 versus 23 +/- 6 years) and greater duration of follow-up after transplantation (3.3 +/- 1.4 versus 1.8 +/- 1.2 years) in group II patients with severe intimal thickening (p < 0.01). Cardiac events were defined as the occurrence of sudden death, myocardial infarction, or the need for coronary revascularization via percutaneous or surgical intervention. One cardiac event occurred in group I patients (sudden death), whereas seven events were noted in the group II patients (p = 0.006). Cardiac events in the group of patients with severe intimal thickening included four patients with sudden cardiac death and three patients who underwent percutaneous revascularization procedures involving directional coronary atherectomy. Angiograms were normal in 62% of patients who had cardiac events.
Conclusions: This study represents one of the first reports that provides evidence that severe intimal hyperplasia predicts the development of cardiac events even in the presence of a normal coronary angiogram.