Risk of Subarachnoid Hemorrhage and Early Case Fatality Associated with Outpatient Antithrombotic Drug Use. Stroke. 2013
Subarachnoid hemorrhage (SAH) constitutes a relatively small percentage of stroke but carries a high risk of morbidity and mortality. There are several well established risk factors, including cerebral artery aneurysms, polycystic kidney disease and hypertension.
In this population based, case-controlled study, Drs. Garbe, et al, broach the issue of outpatient antithrombotic use effect on SAH incidence and early (30-day) case fatality. Their study was performed in Germany from 2004-2006 and includes detailed data on hospitalizations for SAH along with outpatient prescriptions for antirhrombotic medications, including phenprocoumon (warfarin analogue used in Germany), unfractionated or low molecular weight heparins, clopidogrel/ticlopidine and low dose aspirin.
In a multivariable model, phenprocoumon, aspirin and clopidogrel/ticlodipine were independently associated with increased risk for SAH (adjusted ORs 1.7, 1.5, 1.6 respectively). A similar trend was noted for heparin, but the sample was significantly underpowered, likely due to limited use of heparin in the outpatient setting. On the contrary, the early case fatality was not affected by antithrombotic drug use but rather by age (over 70) and hypertension.
Interestingly the study does not include any information regarding smoking status, as it was impossible to gauge this by review of the epidemiologic data. Although it would be interesting to include this variable, the authors’ point that smoking status would be unlikely to significantly affect the question they attempt to answer is probably valid.
In the contrary, one of the strengths of the study is that it represents a “real life scenario”. Those medications are widely used in most of the Western societies where cardiovascular disease predominates as major cause of mortality and morbidity. Besides their better studied bleeding complications, it seems that they also confer increased risk for subarachnoid hemorrhage as well, emphasizing the need to prescribe and use them cautiously.