Prognostic influence of prior ischemic heart disease in in-hospital mortality of acute coronary syndromes

Proper risk stratification in the context of an acute coronary syndrome is a key issue in contemporary cardiology. This work aims to analyze the prognostic implications of pre-existing ischemic heart disease in the in-hospital course of an acute coronary syndrome. This is a retrospective single-center study with 4500 patients admitted with diagnosis of acute coronary syndrome (2004–2010). We evaluated the association between in-hospital mortality and history of ischemic heart disease. For multivariate analysis, logistic regression models were constructed including the GRACE risk score and the history of ischemic heart disease. The study protocol conforms to the ethical guidelines of the 1975 Declaration of Helsinki as reflected in a priori approval by the institution's human research committee. A total of 1076 patients had prior history of ischemic heart disease (23.9%: 2.6% with prior infarction and 11.3% with prior angina). 326 of them (30.3%) had undergone PCI, 234 (21.8%) had undergone CABG and 516 (47.9%) managed conservatively. Patients with prior ischemic heart disease were at increased cardiovascular risk, appearingmore as acute coronary syndrome without ST-segment elevation, with higher rate of multivessel disease and higher rate of systolic dysfunction, and with smaller proportion undergoing coronary revascularization. Patients with known coronary artery disease had a longer hospital stay (11.9 ± 9.5 vs 10.2 ± 9.2 days; p b 0.001). Prior ischemic heart disease was a predictor of in-hospital death in NSTACS (6.3 vs 4.5%, p = 0.035) and in STEMI (13.6 vs 8.1%, p = 0.031). However, only patients with prior myocardial infarction (not angina) that had in the present a NSTACS (not a STEMI) had worse in-hospital prognosis (OR 1.51, CI 95% 1.02–2.24; p = 0.039), as it could be seen in Table 1. especially in those patients who had a infarction and now were presented as an acute coronary syndrome without ST-segment elevation (Odds ratio 1.51, CI 95% 1.02–2.24, P = 0.039). If the prior ischemic heart disease was managed conservatively, the risk increases, being an predictor of in-hospital death independently of GRACE risk score (Odds ratio 1.58, CI 95% 1.06–2.34, P = 0.024). The in-hospital mortality also seemed influenced by theway it was handled prior coronary disease (Fig. 1). Prior ischemic heart disease managed conservatively with medical therapy had a greater risk of death during hospital admission for ACS (OR 1.74, CI 95% 1.24–2.40, P = 0.001), unlike what happened with a history of previous PCI (OR 0.78, CI 95% 0.46–1.30, P = 0.34) or CABG (OR 0.82, CI 95% 0.45–1.48, p = 0.511). In the multivariate analysis, the prior history of a myocardial infarction (OR 1.52, CI 95% 1.01–2.29; p = 0.044) and the conservative