Echocardiographic and hemodynamic determinants of right coronary artery flow reserve and phasic flow pattern in advanced non-ischemic cardiomyopathy

Abstract Background In patients with advanced non-ischemic cardiomyopathy (NIC), right-sided cardiac disturbances has prognostic implications. Right coronary artery (RCA) flow pattern and flow reserve (CFR) are not well known in this setting. The purpose of this study was to assess, in human advanced NIC, the RCA phasic flow pattern and CFR, also under right-sided cardiac disturbances, and compare with left coronary circulation. As well as to investigate any correlation between the cardiac structural, mechanical and hemodynamic parameters with RCA phasic flow pattern or CFR. Methods Twenty four patients with dilated severe NIC were evaluated non-invasively, even by echocardiography, and also by cardiac catheterization, inclusive with Swan-Ganz catheter. Intracoronary Doppler (Flowire) data was obtained in RCA and left anterior descendent coronary artery (LAD) before and after adenosine. Resting RCA phasic pattern (diastolic/systolic) was compared between subgroups with and without pulmonary hypertension, and with and without right ventricular (RV) dysfunction; and also with LAD. RCA-CFR was compared with LAD, as well as in those subgroups. Pearson's correlation analysis was accomplished among echocardiographic (including LV fractional shortening, mass index, end systolic wall stress) more hemodynamic parameters with RCA phasic flow pattern or RCA-CFR. Results LV fractional shortening and end diastolic diameter were 15.3 ± 3.5 % and 69.4 ± 12.2 mm. Resting RCA phasic pattern had no difference comparing subgroups with vs. without pulmonary hypertension (1.45 vs. 1.29, p = NS) either with vs. without RV dysfunction (1.47 vs. 1.23, p = NS); RCA vs. LAD was 1.35 vs. 2.85 (p < 0.001). It had no significant correlation among any cardiac mechanical or hemodynamic parameter with RCA-CFR or RCA flow pattern. RCA-CFR had no difference compared with LAD (3.38 vs. 3.34, p = NS), as well as in pulmonary hypertension (3.09 vs. 3.10, p = NS) either in RV dysfunction (3.06 vs. 3.22, p = NS) subgroups. Conclusion In patients with chronic advanced NIC, RCA phasic flow pattern has a mild diastolic predominance, less marked than in LAD, with no effects from pulmonary artery hypertension or RV dysfunction. There is no significant correlation between any cardiac mechanical-structural or hemodynamic parameter with RCA-CFR or RCA phasic flow pattern. RCA flow reserve is still similar to LAD, independently of those right-sided cardiac disturbances.

The authors specially thank Alfredo J. Mansur, MD, for the critical revising and Felix Ramires, MD, for the English review; Marisa Isaki, MD for nuclear medicine contributions; also Paula Buck, RN, Wilmary Custódio, RN and Irineia Boani, RN, for their helping in data collection; Mittie A. H. Koyama for statistical analysis support; to the Laboratorio Libbs Farmaceutica LTDA, Sao Paulo, Brazil, for its partial financial supporting; and particularly to the patients who participated in this study.

The authors specially thank Alfredo J. Mansur, MD, for the critical revising and Felix Ramires, MD, for the English review; Marisa Isaki, MD for nuclear medicine contributions; also Paula Buck, RN, Wilmary Custódio, RN and Irineia Boani, RN, for their helping in data collection; Mittie A. H. Koyama for statistical analysis support; to the Laboratorio Libbs Farmaceutica LTDA, Sao Paulo, Brazil, for its partial financial supporting; and particularly to the patients who participated in this study.

This study had partial financial supports from EJ Zerbini Foundation, Sao Paulo, Brazil, and from Fundação de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP), Sao Paulo, Brazil.

This study had partial financial supports from EJ Zerbini Foundation, Sao Paulo, Brazil, and from Fundação de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP), Sao Paulo, Brazil.