Are Urinary Tract Infections Linked to Heart Attacks and Strokes?

Urinary tract infections (UTIs) may be a trigger for myocardial infarction (MI) or stroke, with an increased risk for both within the first 7 days of infection, according to the findings of a study published in BMJ Open.

Growing evidence suggests that acute infection plays a role in the pathogenesis of cardiovascular disease.

Researchers from Cardiff University in the United Kingdom conducted this self-controlled cases series using data from the Secure Anonymised Information Linkage (SAIL) Databank which houses nation-wide data from Wales. Patients (N=105,930) with MI (n=51,660) or stroke (n=58,150) between 2010 and 2020 were evaluated for general practitioner suspected or confirmed UTI before or after MI or stroke event. The peak risk period was defined as up to 90 days after UTI.

The MI and stroke cohorts consisted of 63% and 49% men, with mean ages of 69 and 74 years for men and 77 and 79 years for women, respectively.

Among these, 2320 individuals in the MI cohort and 2840 in the stroke cohort had an identified UTI. In the UTI subgroups, men comprised 38.8% and 31.5% of the MI and stroke cohorts, with mean ages of 74 and 78 years, respectively. Women had mean ages of 76 and 79 years, and the electronic Frailty Index (eFI) was 0.23 for the MI group and 0.24 for the stroke group.

The MI cohort collectively had 3900 confirmed UTI events, of which 120 MIs occurred during the peak risk period. Overall risk for MI was higher in the 7 days after UTI (adjusted incidence rate ratio [aIRR], 2.49; 95% CI, 1.65-3.77) and at 15 to 28 days after UTI (aIRR, 1.60; 95% CI, 1.10-2.33).

The stroke cohort collectively had 4600 confirmed UTI events, of which 10 occurred prior to UTI and 200 in the peak risk period. Risk for stroke was higher in the 7 days after UTI (aIRR, 2.34; 95% CI, 1.61-3.40) and at 29 to 90 days after UTI (aIRR, 1.26; 95% CI, 1.05-1.52).

In secondary analyses, MI risk was increased in 8 to 14 days after suspected UTI with mixed bacteria growth on culture (aIRR, 2.07; 95% CI, 1.03-4.15), within 7 days after suspected UTI without urine culture (incidence rate ratio [IRR], 1.83; 95% CI, 1.54-2.18), and within 7 days after suspected UTI with no bacterial growth on culture (IRR, 3.69; 95% CI, 2.28-5.96).

For stroke, risk was higher in the first 7 days of all types of suspected UTI events.

Significant interactions between UTI and Escherichia (E) coli positivity for MI (P <.0001) and stroke (P <.0001) risk were observed, in which the magnitude for MI risk was lower with E coli than other organisms (IRR, 2.55 vs 3.54), whereas the magnitude for stroke risk was higher with E coli than other organisms (IRR, 3.06 vs 2.34), respectively.

This study may have been limited, as the precise date of UTI symptom onset was not known.

“We observed an increased risk of MI and stroke immediately following a UTI. This finding was robust to a range of secondary and sensitivity analyses and warrants further work to better understand mechanisms and inform trials of primary prevention,” the researchers concluded.