Dihydropyridine calcium antagonists increase fibrinolytic activity: a systematic review

Calcium antagonists have been shown to be superior over other antihypertensive drugs to prevent stroke. Because this cannot be fully attributed to blood pressure lowering effects, other mechanisms seem to play a role. Previously we found in patients with subarachnoid hemorrhage that nimodipine enhances fibrinolytic activity. The purpose of this systematic review was to investigate the fibrinolytic effect of calcium antagonists in general, especially in patients with hypertension. We systematically studied the entire PUBMED and EMBASE database with the search terms 'calcium antagonist' combined with 'fibrinolysis', '(euglobulin) clot lysis time' (ECLT), 'tissue plasminogen activator' (tPA), or 'plasminogen activator inhibitor' (PAI). Twenty-six prospective studies were identified and 22 manuscripts were included (802 investigated individuals). The results show that calcium antagonists significantly increase fibrinolysis as shown by a reduction of the ECLT standardized mean differences (SMD) -0.58 (95% confidence interval (CI) -1.05 to -0.11)) and an increase of tPA activity (SMD 0.73 (95% CI 0.25 to 1.21)). This increase of fibrinolysis is apparently caused by an increase of the tPA antigen level (SMD 0.16 (95% CI -0.05 to 0.37)) and a decrease of the plasminogen activator inhibitor-1 antigen antigen (SMD -0.36 (95% CI -0.74 to 0.02)). A sensitivity analysis showed that dihydropyridines, but not phenylalkylamines, exert a fibrinolytic effect. This fibrinolytic effect is not only seen in patients with subarachnoid hemorrhage but also in hypertensive patients. In conclusions, calcium antagonists increase fibrinolytic activity. This may add to the beneficial pharmacological effect of calcium antagonists to prevent ischemic events in patients with hypertension and subarachnoid hemorrhage.