New-onset AF and HF triggered by RSV infection in an elderly patient

Presentation, history and treatment
An 87-year-old lady was hospital­ized for respiratory distress in Janu­ary 2024. When seen at bedside, her blood pressure was 190/110 mm Hg and she had atrial fibrillation (AF). She was also on oxygen support at a rate of 5 L/min. The patient’s history in­cluded hypertension well controlled on an angiotensin receptor blocker, and diabetes well controlled on linagliptin and empagliflozin. She had no known history of coronary artery dis­ease, AF or stroke.

Four days prior to presentation, the patient consulted a general prac­titioner for low-grade fever, a runny nose and copious sputum, which was treated as an upper respirato­ry tract infection with symptom re­lief medications. No antibiotics were prescribed as there was no evidence of bacterial infection. However, her symptoms did not improve, and she deteriorated rapidly over the next 4–5 days leading up to hospitalization.

Chest X-ray revealed signs of heart failure (HF) as well as pneumo­nia in the right lower and right upper zones of the patient’s lungs. (Figure) Respiratory sample tested positive for respiratory syncytial virus (RSV) on polymerase chain reaction assay. The suspected superimposed bacte­rial infection causing pneumonia was managed with antibiotics.

Echocardiography confirmed AF and HF with preserved ejection frac­tion (HFpEF) and very mild mitral re­gurgitation. The patient’s N-terminal pro-B-type natriuretic peptide level was >9,000 pg/mL (reference cut-off for individuals >75 years of age, 1,800 pg/mL), further confirming HF.¹ The AF and HFpEF were like­ly triggered by the RSV infection. A beta-blocker and the calcium chan­nel blocker, diltiazem, were given to manage her AF. Anticoagulation prophylaxis with edoxaban was also ini­tiated to reduce the underlying risk of AF-related stroke.

The patient’s poor medical state necessitated treatment in the inten­sive care unit (ICU) for about 2 weeks. As there is no specific treatment for RSV, only symptomatic treatment and support could be provided. For­tunately, she responded well to treat­ment and could be weaned off oxygen support and was subsequently trans­ferred to the general ward. However, 2 weeks of being bedbound resulted in muscle wasting, which required in-hospital physical rehabilitation to facilitate recovery. The patient was hospitalized for a total of 1.5 months after the acute episode.

Discussion
Respiratory viral infections, in­cluding RSV, have been known to exacerbate underlying cardiovascu­lar disease (CVD) and trigger new CV events, such as acute myocardial in­farction, AF or HF, requiring hospital­ization, as in our patient’s case. These sequelae often result in mortality or long-term morbidity (eg, prolonged physical rehabilitation after ICU stay, as well as new-onset AF and HF on top of previously uncomplicated hy­pertension and diabetes), adding to healthcare utilization burden.²

A cross-sectional analysis of US RSV Hospitalization Surveillance Network data revealed that nearly one-quarter of adults ≥50 years of age hospitalized with an RSV infec­tion experienced an acute cardiac event, of whom 8.5 percent had no documented underlying CVD. Among all the hospitalized patients with RSV infection, 18.6 percent required ICU admission and 4.9 percent died during hospitalization.³

Of note, the likelihood of devel­oping CV complications is greater in those with pre-existing CVD (33 vs 22.4 percent in the overall pop­ulation). Among patients with pre-existing CVD, the most common acute cardiac event was acute HF (25.3 per­cent), followed by acute ischaemic cardiac event (10.2 percent).³

Another retrospective US population-based study of adults ≥18 years old also found increased risk and severity, as well as high burden of RSV-related hospitaliza­tion among those with underlying comorbidities, the elderly and the immunocompromized.⁴

Acute viral infections may exac­erbate the inflammatory process and cellular immune dysfunction associat­ed with vascular conditions, increas­ing CV morbidity and mortality.^5-9

For vulnerable individuals, active im­munization could reduce the risks and impact of infection. One dose of the recombinant adjuvanted RSV vaccine (RSVpreF3) has been found to be efficacious against RSV-related lower respiratory tract dis­ease (LRTD) over three RSV seasons in an ongoing phase III, randomized, placebo-controlled trial across 17 countries spanning the Northern and Southern hemispheres that included 24,967 participants aged ≥60 years (with co-existing chronic respiratory/pulmonary disease, chronic HF, car­diorespiratory disease, type 1 or 2 diabetes, advanced liver or renal disease, 40 percent).¹⁰

Since June 2024, the US Centers for Disease Control and Prevention (CDC) Advisory Committee on Immu­nization Practices (ACIP) has recom­mended a single dose of RSV vac­cine in all adults aged ≥75 years and in those aged 50–74 years with cer­tain chronic medical conditions (eg, CVD, diabetes with end-organ dam­age or lung disease), moderate or severe immunocompromise, severe obesity, and in those who may be at increased risk of severe RSV disease (eg, residents of nursing homes or long-term care facilities).^11,12

The American Heart Association echoes CDC’s recommendations and the 2024 American College of Cardiology Expert Consensus rec­ommended vaccinations against viral infections (such as RSV) in patients with HF.^13,14

In Hong Kong, RSVPreF3 is ap­proved for use in adults ≥60 years old to prevent RSV-related LRTD and adults 50–59 years of age who are at increased risk for RSV disease, and is recommended by the Hong Kong Medical Association.^15,16

From the author’s clinical expe­rience, diagnosis of RSV infection could be delayed because patients generally have low-grade fever, which is less likely to prompt early medical attention than high fever more com­monly seen with influenza. Patients also often attribute the symptoms to common cold or influenza and ignore the cough and copious sputum un­til they become seriously ill, as in the case of our patient.

As there is currently no specific treatment for RSV infection, vaccina­tion is key in preventing RSV-related morbidity and mortality. The elderly, particularly those with diabetes and/or underlying CVD, should thus be educated and encouraged to vacci­nate when they present to clinics for follow-up visits.

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