Article Text
Abstract
Introduction A decrease in myocardial capillary density is the dominant mechanism of microcirculatory dysfunction in many conditions. Conventional intracoronary tools struggle to quantify this because of their relatively non-specific interrogation of the microvasculature. We investigated the potential of wave intensity analysis (WIA) to ascertain capillary density in cardiac transplantation patients and then used this relationship to predict the development of cardiac allograft vasculopathy (CAV).
Methods 44 patients with unobstructed arteries underwent rest and hyperaemic LAD pressure and flow measurements. CFR, HMR, IHDVPS and WIA were calculated. Simultaneous right ventricular biopsies were obtained and analysed for capillary density in 15 patients. All patients were then followed up with 1–3 yearly screening angiography.
Results All patients were in sinus rhythm with normal LV function. A statistically significant relationship with capillary density was noted with CFR (r = 0.52, p = 0.048) and the backward decompression wave (BDW) (r=-0.65, p < 0.01) - only the latter was maintained with multiple regression analysis (p = 0.02). Mean follow-up was 9.3 ± 5.2 years. Only the BDW was able to predict outcome in terms of CAV-events (p = 0.04) as well as the development (p = 0.01), severity (p = 0.04) and rate (p = 0.09) of angiographic CAV
Conclusions WIA is an excellent tool for assessing capillary density. In transplant patients it is able to document the earliest histological changes of CAV and can predict CAV-related outcome as well as its angiographic development and severity.