CDC Finds Recovery Common After Rare Vaccine-Related Myocarditis

Most patients who develop a rare myocarditis following COVID-19 mRNA vaccination make a full recovery and regain their prepandemic quality of life at least 90 days after the Centers for Disease Control and Prevention (CDC) study of the results Diagnosis.

Case reports suggest that the results of the rare occurrence of post-vaccination myocarditis, which occurs more frequently in young adult males, are more favorable than those associated with viral infection. Although these reports describe symptoms resolving before or shortly after discharge from the brief hospital setting, CDC investigators note that the intermediate term after diagnosis is unclear.

“Data on follow-up prognosis of adolescents and young adults diagnosed with myocarditis after mRNA-COVID-19 vaccination is scarce,” noted Ian Kracalik, PhD, and colleagues on the CDC COVID-19 Response Team, US CDC, Atlanta, GA, fixed.

To identify outcomes that may persist or occur over time, Kracalik and colleagues conducted the largest surveillance of these patients to date, with follow-up interviews with patients and/or their healthcare providers at least 90 days after diagnosis (median 143 days ).

Among tests of cardiac status and cardiac function, the investigators looked for new data on scarring after myocarditis by the presence of late gadolinium enhancement and residual edema on cardiac MRI. In addition, they collected and compared EuroQol’s health-related quality of life measures to assessments published in the US population before and at the onset of the COVID-19 pandemic.

Data were collected for 519 patients who were at least 90 days after onset of myocarditis; 126 were contacted through a patient survey, 162 through their healthcare provider survey, and 231 through both surveys. The mean patient age was 17 years, with 88% being male.

Investigators report that 320 (81%) of the 393 patients with a physician evaluation were determined to have recovered from myocarditis; with 268 [68%] of 393 patients were released for all physical activities at the follow-up examination. However, 104 (26%) were prescribed medications related to myocarditis on a daily basis.

Of 249 patients who completed the quality of life portion of the survey, 4 (2%) reported problems with self-care, 13 (5%) problems with mobility, 49 (20%) with performing usual activities, 74 ( 30% ) with pain and 114 (46%) with depression. The researchers calculated the mean weighted measure of quality of life (0.92, [SD 0.13]) similar to a pre-pandemic US population value of 0.92 (SD 0.13) and significantly higher than a pre-pandemic US population value of 0.75 (SD 0.28).

Most patients had improvements in cardiac diagnostic markers and test data, including normal or return to baseline troponin concentrations, echocardiograms, electrocardiograms, exercise stress testing, and ambulatory rhythm monitoring. An abnormality was detected in 82 (54%) of the 151 patients with follow-up MRI of the heart, but signs of late gadolinium enhancement myocarditis and/or edema were uncommon (20 [13%] of 151 patients).

In an accompanying comment, Enrico Ammirati, MD, PhD, De Gasperis Cardio Center, Niguarda Hospital, Milano, Italy, and Leslie Cooper Jr, MD, Department of Cardiovascular Medicine, Mayo Clinic, Jacksonville, Fla., noted that survey responses from patients described more symptoms of myocarditis than those of their providers.

“This comparison underscores the need to seek patient-reported outcomes rather than relying solely on physiological or biochemical metrics to identify full recovery,” Ammirati and Cooper said.

They also emphasize that finding less severe and less frequent myocarditis after mRNA vaccination than has been historically associated with viral infection “should help resolve the dilemma between vaccination and non-vaccination.”

“Healthcare providers and individuals should be reassured by the high cardiac recovery rate in mRNA-COVID-10 vaccine-associated myocarditis,” Ammirati and Cooper note.