Author + information
- Lovely Chhabra, MD and
- N. Gurukripa Kowlgi, MBBS∗ ()
- ↵∗Hartford Hospital, University of Connecticut School of Medicine, 80 Seymour Street, Hartford, Connecticut 06102
We immensely enjoyed reading the recently published article by Sara et al. (1) in JACC: Cardiovascular Interventions. Their endeavors to elucidate the spectrum of coronary microvascular abnormalities in patients with chest pain and nonobstructive coronary artery disease are commendable (1). In summary, they found that microvascular dysfunction occurred in two-thirds of these patients, and interestingly these were poorly associated with the conventional risk factors. This study echoes the results found by previous studies demonstrating the role of microvascular dysfunction in this patient population.
In their findings, we paid special attention to the low incidence of diabetes mellitus reported among all the study groups (7% to 12%). We would like to switch gears and bring the readers’ attention to a curious similarity between the population in this study and patients with Takotsubo cardiomyopathy (TC). A recent meta-analysis showed that the prevalence of diabetes mellitus in patients with TC was indeed low (2). This fact has been reproduced in subsequent smaller studies. It has been suggested that the blunted catecholamine secretions (autonomic neuropathy) may perhaps be protective against the development of TC (3,4). The success of sympathetic blockade for TC in animal model studies has further supported this hypothesis. It has long been accepted that diabetes mellitus is one of the strong risk factors for coronary microcirculatory disease (5), and the low incidence of diabetes in this study group was peculiar. It almost leads us to wonder whether there might be an overlap of some of these patients with TC, especially with atypical or chronic recurrent forms of TC. That potentially would explain the low incidence of diabetes, and the presence of microcirculatory dysfunction is consistent with the described pathophysiology of TC. Also, this thought-provoking correlation is compelling to suggest that female patients with microvascular dysfunction perhaps may have a unique nontraditional etiological background, for example, they seem less likely to be affected by diabetes mellitus (because both the current study population and previous TC studies demonstrated a female predominance) (1,2).
Although the authors were meticulous in their efforts, another aspect that caught our attention was the analysis of cardiac studies, specifically echocardiography and stress testing. The study duration was 20 years, and it is apparent that imaging parameters may vary considerably over time depending on the disease progression or risk-factor modification. It is not clear from their article at what point imaging was performed, and this might have some impact on the analysis of outcomes. The addition of that information could allow a more robust interpretation of these data. Future prospective studies are needed for a better understanding of the role of autonomic influences and clinical markers regarding their association with microvascular dysfunction.
Please note: The authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- 2016 American College of Cardiology Foundation
- Sara J.D.,
- Widmer R.J.,
- Matsuzawa Y.,
- Lennon R.J.,
- Lerman L.O.,
- Lerman A.
- Madias J.E.
- Chhabra L.,
- Sareen P.
- Khalid N.,
- Chhabra L.