An Interrupted Time-Series Analysis of the Impact of COVID-19 on Hospitalizations for Vascular Events in 3 Canadian Provinces

Abstract

Background

COVID-19 infection is associated with a pro-coagulable state, thrombosis, and cardiovascular events. However, its impact on population-based rates of vascular events is less well understood. We studied temporal trends in hospitalizations for stroke and myocardial infarction in 3 Canadian provinces (Alberta, Ontario, and Nova Scotia) between 2014 and 2022.

Methods

Linked administrative data from each province were used to identify admissions for ischemic stroke, intracerebral hemorrhage, cerebral venous thrombosis, and myocardial infarction. Event rates per 100,000/quarter, standardized to the 2016 Canadian population, were calculated. We assessed changes from quarterly rates pre-pandemic (2014-2020), compared to rates in the pandemic period (2020-2022), using interrupted time-series analysis with a jump discontinuity at pandemic onset. Age group– and sex-stratified analyses also were performed.

Results

We identified 162,497 strokes and 243,182 myocardial infarctions. At pandemic onset, no significant step change in strokesper 100,000/quarter was observed in any of the 3 provinces. During the pandemic, stroke rates were stable in Alberta and Ontario, but they increased in Nova Scotia (0.44 per 100,000/quarter, P = 0.004). At pandemic onset, a significant step decrease occurred in myocardial infarctions per 100,000/quarter in Alberta (4.72, P < 0.001) and Ontario (4.84, P < 0.001), but not in Nova Scotia. During the pandemic, myocardial infarctions per 100,000/quarter decreased in Alberta (–0.34, P = 0.01), but they remained stable in Ontario and Nova Scotia. No consistent patterns by age group or sex were noted.

Conclusions

Hospitalization rates for stroke or myocardial infarction across 3 Canadian provinces did not increase substantially during the first 2 years of the pandemic. Continued surveillance is warranted as the virus becomes endemic.