Microbiologically confirmed urinary tract infections were followed by a significantly increased short-term risk of myocardial infarction and stroke, with the highest risk occurring in the first 7 days following infection, according to a study of medical records in Wales.
Researchers analyzed data from 51,660 individuals hospitalized for a first myocardial infarction (MI) and 58,150 for a first stroke between January 1, 2010, and December 31, 2020. Among them, 2,320 with MI and 2,840 patients with stroke also had at least one confirmed urinary tract infection (UTI) during the study period.
Using a self-controlled case series design, each patient served as their own control to reduce confounding from factors that do not change over time, such as sex or genetics. The incidence of MI and stroke during specific risk windows after infection was compared with baseline periods.
In the 1 to 7 days following infection, the risk of MI was significantly elevated, based on 20 MI events for 27,049 person-days, compared with 2,190 events during 8,102,743 baseline person-days. A smaller increase was observed during days 15 to 28. No significant risk increase was noted in days 8 to 14 or 29 to 90.
Stroke risk was also higher in the first 7 days after infection), with 30 events for 31,944 person-days. A modest increase persisted during days 29 90, but not during days 8 to 28.
To qualify as microbiologically confirmed, a UTI episode required a general practitioner diagnosis, an antibiotic prescription, and a urine culture showing significant bacterial growth and elevated white blood cells.
Analyses including suspected infections without microbiological confirmation also showed increased cardiovascular risk in the first week of infection.
The type of bacteria also appeared to influence outcomes. Stroke risk was higher after UTIs caused by Escherichia coli compared with other organisms. Differences for myocardial infarction risk were less marked.
Findings were consistent across sensitivity analyses adjusting for age, season, year, microbiological thresholds, and antibiotic use.
“UTI may be a trigger for MI or stroke. Further work is needed to understand mechanisms and test interventions to reduce the risk of cardiovascular events among people with UTIs in primary care,” Nicola F. Reeve from Cardiff University, UK, and researchers concluded.
Full disclosures can be found in the study.
Source: BMJ Open
