Cardiac and central vascular functional alterations in the acute phase of aneurysmal subarachnoid hemorrhage

Abstract

Objectives: To investigate aortic functional alterations in the acute phase of aneurysmal subarachnoid hemorrhage and to evaluate the relationship between potential cardiovascular alterations and delayed cerebral infarctions or poor Glasgow Outcome Scale score at discharge from critical care unit. Design: Prospective observational study. Setting: Critical Care Departments of two tertiary centers. Patients: Thirty-seven patients with aneurysmal subarachnoid hemorrhage. Interventions: Patients were evaluated at two time points: on admission (acute aneurysmal subarachnoid hemorrhage phase) and at least 21 days later (stable aneurysmal subarachnoid hemorrhage state). At baseline, the severity of aneurysmal subarachnoid hemorrhage was assessed clinically (Hunt and Hess scale) and radiologically (brain computed tomography Fisher grading). Aortic elasticity was evaluated by Doppler-derived pulse-wave velocity and left ventricular function by echocardiography. Serum B-type natriuretic peptide and troponin I were also assessed at the same time points. Measurements and Main Results: At the acute phase, 23 patients (62%) were found to present supranormal pulse-wave velocity and 14 patients (38%) presented left ventricular systolic dysfunction; there were significant associations between pulse-wave velocity values and left ventricular ejection fraction (p <= .001). Left ventricular ejection fraction and pulse-wave velocity were both associated with Hunt and Hess (p < .004) and Fisher grading (p <= .03). Left ventricular ejection fraction and pulse-wave velocity were improved between acute aneurysmal subarachnoid hemorrhage and stable state (p <= .005); changes (Delta%) were greater in patients who initially had regional wall motion abnormalities compared to patients who had not (28.7% +/- 10.2% vs. 2.4% +/- 1.8% [p = .002] and -17.9% +/- 3.7% vs. -3.5% +/- 4.7% [p = .045], respectively). Pulse-wave velocity/left ventricular ejection fraction ratio was the only independent predictor for delayed cerebral infarctions. Left ventricular ejection fraction, B-type natriuretic peptide, pulse-wave velocity, and pulse-wave velocity/left ventricular ejection fraction showed significant diagnostic performance for predicting delayed cerebral infarctions or poor Glasgow Outcome Scale score (1-3). Conclusions: Our findings suggest that significant cardiovascular alterations in left ventricular function and in aortic stiffness occur during the early phase of aneurysmal subarachnoid hemorrhage. These phenomena were associated with adverse outcomes in this study and their role in the pathogenesis of delayed neurologic complications warrants further investigation. (Crit Care Med 2012; 40:223-232)