Outcomes of patients hospitalized for suspected acute coronary syndrome, in whom the diagnosis was not confirmed: Results from the CZECH-1 and CZECH-2 registries

BackgroundSuspicion of acute coronary syndrome (ACS) is one of the most common reasons for hospital admission. However, ACS is not confirmed in a high proportion of these patients during hospitalization. Very few details exist about these patients.AimTo evaluate the clinical characteristics and outcomes of hospitalized patients with a suspicion for ACS that has not been confirmed and compare these results with patients with confirmed ACS.Methods and resultsData were used from the CZECH-1 and CZECH-2 registries, collected in November 2005 and October–November 2012. Both registries contain data from all consecutive patients who have been hospitalized with an initial diagnosis of ACS. ACS was not confirmed during hospitalization in 578 of 1921 patients (30.1%) in the CZECH-1 registry and in 372 of 1221 (30.5%) in the CZECH-2 registry. In both registries, higher proportions of females (52 vs. 36%; p < 0.001 and 46 vs. 33%; p < 0.01, respectively) were observed between patients with unconfirmed ACS compared to those with confirmed ACS. A history of myocardial infarction was known in 25% of the patients with unconfirmed ACS in both registries. On admission, atrial fibrillation or other non-sinus rhythm on ECG was present in 17% of patients with unconfirmed ACS, bundle branch block in 18%, ST depression in 8%, and ST elevation in 3.6%. Coronary angiography was performed on 36% of these patients in CZECH-1 and 27% of patients in CZECH-2 (p < 0.01). In-hospital mortality of the ACS unconfirmed patients was 1.2% in the CZECH-1 registry and 2.1% in the CZECH-2 registry (p = NS). 30-day and 1-year mortality in patients with unconfirmed ACS in the CZECH-2 registry were significantly lower compared to patients with confirmed ACS (3.5 vs. 6.6%; p < 0.05 and 6.5 vs. 13%; p < 0.05, respectively). Musculoskeletal pain and acute heart failure were the most common discharge diagnosis in patients with unconfirmed ACS.ConclusionHospitalized patients in whom the suspicion of ACS had not been confirmed were more often female and a high proportion had abnormal ECG on admission. In-hospital mortality was very low, and the 1-year mortality was significantly lower compared to patients with confirmed ACS.