Stroke and rheumatic heart disease: a systematic review of observational studies

Ischemic stroke is a severe complication of rheumatic heart disease (RHD), but data about its incidence and case-fatality in RHD patients' population is unclear. We aimed to perform a systematic review of the literature to better define the incidence, prevalence and case-fatality of stroke in patients with RHD, and to estimate the proportion of RHD in stroke population. We searched Ovid Medline, EMBASE, CBM, CNKI and VIP for observational studies published in English or Chinese reporting the association of stroke and RHD until April 2011. Two authors independently assessed each study for eligibility based on pre-defined criteria in a two-step approach and then made a final decision. Twenty-one studies, involving 26994 participants, were deemed eligible (albeit of low quality) and included in our analysis. Two studies reported stroke incidence in RHD patients' population, which was 4.5 per 100 patient years in America by 1978 and 5.9 per 100 patient years in China 30 years later. Eight studies reported stroke prevalence in RHD patients' population. It ranged from 0.37% to 12.6% in Asia in last 30 years. Ten studies reported the proportion of RHD in stroke patient. The proportion of RHD in patients with ischemic stroke ranged from 3.4% to 23.2% in Asia and 1.8% to 2.0% in Europe and Northern America during the past 3 decades. Six studies reported case-fatality in stroke patients with RHD. It was 49.2% in America by 1951, and ranged from 8.5% to 47.4% in Asia during last 3 decades. These data suggest that stroke due to RHD remains a hidden burden that cannot be ignored in developing areas such as Asia.