Impact of cardiac complications on outcome after aneurysmal subarachnoid hemorrhage: a meta-analysis.

UNLABELLED

Impact of cardiac complications after aneurysmal subarachnoid hemorrhage (SAH) remains controversial. We performed a meta-analysis to assess whether EKG changes, myocardial damage, or echocardiographic wall motion abnormalities (WMAs) are related to death, poor outcome (death or dependency), or delayed cerebral ischemia (DCI) after SAH.

METHODS

Articles on cardiac abnormalities after aneurysmal SAH that met predefined criteria and were published between 1960 and 2007 were retrieved. We assessed the quality of reports and extracted data on patient characteristics, cardiac abnormalities, and outcome measurements. Poor outcome was defined as death or dependence by the Glasgow Outcome Scale (dichotomized at < or = 3) or the modified Rankin scale (dichotomized at > 3). If studies used another dichotomy or another outcome scale, we used the numbers of patients with poor outcome provided by the authors. We calculated pooled relative risks (RRs) with corresponding 95% confidence intervals for the relation between cardiac abnormalities and outcome measurements.

RESULTS

We included 25 studies (16 prospective) with a total of 2,690 patients (mean age 53 years; 35% men). Mortality was associated with WMAs (RR 1.9), elevated troponin (RR 2.0) and brain natriuretic peptide (BNP) levels (RR 11.1), tachycardia (RR 3.9), Q waves (RR 2.9), ST-segment depression (RR 2.1), T-wave abnormalities (RR 1.8), and bradycardia (RR 0.6). Poor outcome was associated with elevated troponin (RR 2.3) and creatine kinase MB (CK-MB) levels (RR 2.3) and ST-segment depression (RR 2.4). Occurrence of DCI was associated with WMAs (RR 2.1), elevated troponin (RR 3.2), CK-MB (RR 2.9), and BNP levels (RR 4.5), and ST-segment depression (RR 2.4). All RRs were significant.

CONCLUSION

Markers for cardiac damage and dysfunction are associated with an increased risk of death, poor outcome, and delayed cerebral ischemia after subarachnoid hemorrhage. Future research should establish whether these cardiac abnormalities are independent prognosticators and should be directed toward pathophysiologic mechanisms and potential treatment options.