Inconclusive cardiac stress echocardiography and the utility of the double product in predicting outcomes: Early results
Nakhle A, Hammond C, Giles C, Alimirah M, Mand R, Ali M, Mahan M, Ananthasubramaniam K. Inconclusive cardiac stress echocardiography and the utility of the double product in predicting outcomes: Early results. J Am Soc Echocardiogr. 2018;31(6):B127.
J Am Soc Echocardiogr
Background: Stress echocardiography (SE) is one of thefrequently used methods in assessing for coronary ischemia in patients with chest pain. Inconclusive SE, defined as the inability to achieve > 85% of maximal predicted heart rate (MPHR), poses a challenge for clinicians. The aim of our study is to evaluate patients with submaximal SE and see if the value of the double product(DP) could further delineate long term risk better in this patient population. Methods: Six hundred and forty five patients who underwent either chemical or treadmill SE between Jan-June 2013 who had submaximal (≤ 85%) MPHR were retrospectively reviewed. Demographics, medical history, and cardiac stress testing reports were collected. Then, 4 years adverse outcomes, defined as a development of systolic heart failure, myocardial infarction, and death were documented and analyzed, and additional downstream testing (repeat stress testing, myocardial perfusion imaging, or coronary angiography) were collected. Results: Mean age was 59.6 years, and 55% were males. Caucasians represented 47%, and 46% were African Americans (AA). History of myocardial infarction and heart failure was reported in 33% and 19%, respectively. Composite outcome was found in 132 (20%) of all patients. Patients with adverse events were older (64.1, vs. 58.5, P≤0.001), males (65.9% males vs. 34.1% females, P 0.004), Caucasian (54.6% Caucasians, vs. 39.4% AA, P 0.044), and with higher incidence of CAD, and CHF. The univariate odds ratio for the relationship between DP and the composite outcome indicated that for every 1,000-unit increase in DP, the odds of an adverse outcome decrease by 9.1% ([5.5%-12.6%], P≤0.001). Conclusion: Inconclusive SE currently poses a dilemma and many times leads to further testing to reach conclusive decisions for presence or absence of CAD Our study showed that younger, AA females, with no history of CAD or CHF, who were able to achieve a higher value of DP, have a favorable long term outcome with less subsequent adverse events or death aft er 4 years. Thus patients with these characteristics with a negative submaximal SE could be triaged for observation with additional evaluation reserved if they continue to have symptoms. Although traditionally a DP of 24,000 is considered adequate workload DP response may vary for pharmacologic versus exercise stress testing, and thus may help stratify patients when viewed as a continuum.