Abstract 19355: Assessment of Myocardial Capillary Rarefaction Using Intracoronary Wave Intensity Analysis: A Validation in Cardiac Allograft Patients With Resultant Prognostic Insights
Introduction: A decrease in capillary density (capillary rarefaction) is the predominant mechanism of microcirculatory dysfunction in certain heart conditions. Measuring capillary rarefaction with coronary flow reserve (CFR) or resistance measurements is hampered by the frequent presence of arteriolar remodelling. We investigated the potential of wave intensity analysis (WIA) to ascertain the presence of capillary rarefaction using transplant vasculopathy as a clinical model of microcirculatory disease. The prognostic implications of WIA-assessed capillary density in predicting cardiac allograft vasculopathy (CAV) was then also investigated.
Methods: 52 patients with unobstructed coronary arteries underwent combined LAD pressure and flow measurements at rest and with intracoronary adenosine. CFR, hyperaemic microvascular resistance, coronary resistance index, coronary conductance (IHDVPS) and WIA were calculated. Simultaneous right ventricular biopsies were obtained and analysed for capillary density in 17 patients. All patients were then followed up with 1-3 yearly screening angiography and IVUS.
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) the latter of which was maintained with multiple regression analysis (p=0.02). Over a mean follow-up of 9.3 ± 5.2 years, the BDW was able to predict outcome in terms of CAV-events (-7.1 vs -4.5 x103 Wm-2s-1, p=0.04) as well as the development (7.9 vs 4.8 x103 Wm-2s-1, p=0.01) and severity (p=0.04) of angiographic CAV. There was a strong trend towards prediction of angiographic CAV disease with IHDVPS (1.7 vs 1.1 cm/s/mmHg, p=0.08) but no other relationships were noted with prognosis and microvascular indices.
Conclusions: WIA is an excellent tool for assessing capillary rarefaction and provides a more focused insight into this domain of the microcirculation than other contemporary measures of microcirculatory function. In cardiac transplant patients, it is able to document the early histological changes of CAV and can predict CAV-related outcome as well as its angiographic presence and severity.
Author Disclosures: C.J. Broyd: None. F. Hernández-Pérez: None. M. Echavarria-Pinto: None. A. Quirós-Carretero: None. P. García-Pavía: None. C. Salas: None. P. Jiménez-Quevedo: None. N. Gonzalo: None. I. Nuñez-Gil: None. B. Ibañez: None. L. Alonso-Pulpón: None. A. Fernández-Ortiz: None. J. Davies: None. J. Segovia: None. J. Escaned: None.
- © 2015 by American Heart Association, Inc.