Background: Right ventricular dysfunction (RVD) is a major cause of morbidity and mortality in the setting of acute inferior wall myocardial infarction (IWMI), and early detection may improve clinical outcomes. We defined a novel hemodynamic index, the pulmonary artery pulsatility index (PAPi), and explored whether the PAPi correlates with severe RVD in acute IWMI.
Methods: From 2008 to 2010, we identified 20 patients presenting with angiographically confirmed proximal right coronary artery occlusion and suspected RVD (sRVD) as defined by hemodynamic instability, profound bradycardia, or ST-elevation in lead V4R. Two controls groups were studied (1) 50 patients with nonobstructive coronary artery disease (Non-CAD) and (2) 14 patients presenting with acute coronary syndrome requiring left coronary stenting (ACS). Hemodynamic indices analyzed at the time of catheterization included: (1) the right atrial to pulmonary capillary wedge pressure ratio (RA:PCWP), (2) right ventricular stroke work (RVSW), and (3) the PAPi. Qualitative echocardiographic scores of RV systolic function were determined by two blinded investigators within 24 hr of catheterization.
Results: Among subjects with sRVD, 7 (35%) received a percutaneous RV support device (pRVSD) for medically refractory RV failure and 4 (20%) died prior to hospital discharge. Compared to Non-CAD and ACS controls, subjects with sRVD had a significantly lower PAPi (4.32 ± 3.04 vs. 5.52 ± 4.40 vs. 1.11 ± 0.57, respectively, P < 0.01) and a higher RA:PCWP ratio (0.48 ± 0.24 vs. 0.51 ± 0.26 vs. 0.81 ± 0.30, respectively, P < 0.05). Both the PAPi and RA:PCWP ratios correlated significantly with RVSW and qualitative echocardiographic grading. The PAPi demonstrated the highest sensitivity (88.9%) and specificity (98.3%) for predicting in-hospital mortality and/or requirement of a pRVSD. Using ROC curve derived cut-points, a PAPi ≤ 0.9 provided 100.0% sensitivity and 98.3% specificity (C-statistic: 0.998) for predicting these outcomes, exceeding the predictive value of the RA:PCWP ratio or RVSW.
Conclusions: The PAPi is a simple, invasive hemodynamic measure that may help identify high-risk patients with acute IWMI with severe RVD. Earlier identification of this high-risk population may improve clinical outcomes.
Copyright © 2011 Wiley Periodicals, Inc.