TOPLINE:

Respiratory syncytial virus (RSV) infection in adults aged 45 years or older was significantly linked to a higher risk for specific and serious cardiovascular events such as arrhythmias, heart failure, and stroke over the following year, with the risk being similar to that observed after influenza infection; the risk was evident within the first 30 days after infection.

METHODOLOGY:

• This register-based cohort study in Denmark estimated the 365-day absolute excess risk for cardiovascular events after laboratory-confirmed RSV infection among 17,494 participants (mean age, 71.8 years; 57.6% women).
• Participants with laboratory-confirmed RSV infection (n = 8747) were matched to control participants without a positive RSV test (n = 8747) on the basis of age, sex, and preexisting comorbidities.
• Separate matched cohorts compared cases of RSV infection with participants who had a new diagnosis of laboratory-confirmed influenza infection, hip fracture, or urinary tract infection without sepsis.
• Study outcomes were composite measures: major adverse cardiovascular events (MACEs) — ischaemic heart disease, stroke, and heart failure — and any cardiovascular event — MACEs, venous thromboembolism, arrhythmias, and inflammatory heart disease.
• The follow-up duration was 365 days after the index date, defined as the date of the first RSV-positive test for cases.

TAKEAWAY:

• At 365 days, 665 vs 257 any cardiovascular events occurred among cases of RSV infection vs control participants, corresponding to risk differences of 4.69 percentage points (95% CI, 4.02-5.36) for any cardiovascular event and 2.37 percentage points (95% CI, 1.86-2.88) for MACEs.
• The excess risk was evident at 30 days after infection, with risk differences of 3.82 percentage points (95% CI, 3.37-4.26) for any cardiovascular event and 1.64 percentage points (95% CI, 1.33-1.95) for MACEs. Arrhythmias and heart failure contributed to the largest excess risk differences at both 30 and 365 days.
• The 365-day excess risk difference for any cardiovascular event was most pronounced among hospitalised patients, adults aged 85-94 years, and those with preexisting cardiovascular disease or diabetes.
• The risk for any cardiovascular event following RSV infection was comparable to that observed after influenza infection throughout the follow-up period.

IN PRACTICE:

"This study should prompt heightened clinical vigilance for cardiovascular complications following RSV infection and reinforces the public health rationale for preventive measures, most notably vaccination, in older adult populations to mitigate this burden," the authors wrote.

SOURCE:

This study was led by Anders Hviid, MSc, DrMedSci, Statens Serum Institut, Copenhagen, Denmark. It was published online on December 08, 2025, in JAMA Network Open.

LIMITATIONS:

Because the study was conducted in a relatively homogeneous population of Denmark within a universal healthcare system, the findings may not generalise to other settings. Unmeasured lifestyle or sociodemographic factors could have influenced the results. Some RSV infections in the control group likely went undetected.

DISCLOSURES:

No specific funding was reported in this study. Several authors reported receiving grants and presentation, consulting, or lecture fees from foundations and various pharmaceutical companies, and one author reported serving on the scientific board of VAC4EU.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.