Author + information
- Dimitri C. Cassimatis, MD (, )
- J. Edwin Atwood, MD, FACC,
- Renata M. Engler, MD,
- Peter E. Linz, MD, FACC,
- Robert E. Eckart, DO,
- Marina N. Vernalis, DO, FACC and
- John D. Grabenstein, PhD
We appreciate the comments on our review (1) of myopericarditis associated with smallpox vaccination. The recently published rates of myopericarditis may indeed be underestimates, for they are based on reporting of clinical encounters with symptomatic patients from an occupational cohort, as we noted previously (2). To better assess the true incidence rate, we will soon enroll volunteers in a prospective trial of smallpox vaccinees with baseline and follow-up electrocardiography, laboratory markers, and questionnaires.
We described the need to follow patients diagnosed with postvaccinial myopericarditis to establish whether long-term sequelae exist (1), and we recently have published the results of such follow-up (3). On the basis of these data, long-term sequelae are not yet apparent, and recovery rates based on objective markers are high. We intend to continue follow-up for the next two to five years, while looking for evidence of any long-term sequelae.
The utility of endomyocardial biopsy after smallpox vaccination is uncertain. Given the inherent risks and low diagnostic yield of endomyocardial biopsy (1,4), as well as the high likelihood of full objective recovery after smallpox vaccine-associated myopericarditis (3), we would be remiss to recommend a potentially harmful procedure in allpatients with depressed left ventricular function.
Although there has been one case of eosinophilic myocarditis that improved shortly after receiving corticosteroids (5), this one case is insufficient to conclude that corticosteroids will always be beneficial, even when eosinophils are seen on biopsy. However, the possibility that corticosteroids may uniquely benefit patients with eosinophilic myocarditis does warrant continued evaluation. Therefore, although we support endomyocardial biopsy in patients with symptomatic moderate or worse left-ventricular dysfunction related temporally to smallpox vaccination, we caution that every case must be considered individually.
- American College of Cardiology Foundation