Mpilo Outcomes for Stroke Study (MOSS): Does taking antihypertensives prior to stroke affect mortality during acute stroke admissions?

Objective To assess if taking outpatient antihypertensives prior to stroke onset influences acute stroke inpatient mortality. Design Retrospective chart review of 417 adults admitted for acute stroke from January 2013 to December 2014. Setting Single tertiary hospital in Zimbabwe. Participants Of the 417 adult patients admitted with stroke, 40 were excluded (2 rheumatic heart disease, 10 transient ischemic attacks, and 28 incomplete documentation). Methods Study registry was obtained from acute stroke billing codes in the hospital database and SPSS 23 was used for analysis. Primary and secondary outcomes and measures Inpatient mortality was the primary outcome and determination of reported outpatient antihypertensive regimens was the secondary outcome. Results Among the 377 patients in the final analysis the mean age was 65.8 ± 15.7 years, 64.5% were female, 68.9% had known hypertension, and 51.2% were taking outpatient antihypertensives. Overall inpatient mortality was 134 (35.5%, 95 CI: 30.6 -39.6). Mortality was similar among patients taking and not taking outpatient antihypertensives, 39.2% and 31.5% respectively ( X 2 test, p=0 . 4; 95 CI 31.3-40.3). Four most common antihypertensive regimens were: calcium channel blocker/thiazides dual therapy, thiazide monotherapy, calcium channel blocker monotherapy, and calcium channel blocker/ angiotensin converting enzyme inhibitor or angiotensin receptor blocker dual therapy. Conclusions and Relevance Only half of the patients admitted for stroke were taking antihypertensives prior to stroke onset. There was no statistical significance in inpatient mortality associated with taking antihypertensives prior to developing stroke, suggesting either the limited impact of outpatient antihypertensives on in-hospital mortality or low outpatient antihypertensive adherence. Strengths and Limitations of the Study We studied a large group of patients at a major safety net center in a region of Zimbabwe that is chronically under-represented in stroke studies The degree of outpatient hypertension control among patients on antihypertensives could not be determined due to lack of access to outpatient records Poor medical knowledge, altered mental status from stroke, and the absence of an integrated outpatient pharmacy database limited accurate medication reconciliations Lack of neuroimaging data limited the ability to discern between ischemic versus hemorrhagic strokes and rule out structural stroke mimics such as intracranial tumors Inconsistent and incomplete documentation practices such as omission of vital sign documentation on admission limited data collection Funding Statement This research received no specific grant from any funding agency in the public, commercial or not-for-profit sectors. Competing Interests None of the authors have any competing interests to declare. Statement of Ethics Approval This research was approved by the ethics body of Mpilo Central Hospital on 21 June 2016 as part of the mandate to assess The Burden of Hypertension and its Co-morbidities in Patients Admitted at Mpilo Central Hospital.