Nuclear cardiology in the literature: A selection of recent, original research papers

Abstract

Brittany N. Weber, Emma Stevens, Lourdes M. Perez-Chada, Jenifer M. Brown, Sanjay Divakaran, Camden Bay, Courtney Bibbo, Jon Hainer, Sharmila Dorbala, Ron Blankstein, Viviany R. Taqueti, Joseph F. Merola, Elena Massarotti, Karen Costenbader, Katherine Liao, Marcelo F. Di Carli Boston, MA JACC Cardiovasc Imaging. 2021 Mar 10: S1936878X (21)00072-3. Context: Autoimmune systemic inflammatory diseases are associated with increased cardiovascular (CV) risk. Systemic inflammation perturbs vascular endothelial and smooth muscle cell function and has been linked to coronary vasomotor dysfunction. Methods and Results: To determine the prognostic value of impaired coronary vasodilator reserve in patients with common autoimmune systemic inflammatory diseases, the authors conducted a retrospective study of 198 consecutive patients [systemic lupus erythematosus (SLE) 20.7%, psoriasis (PsO) 31.8%, and rheumatic arthritis (RA) 47.5%] who underwent clinically indicated cardiac positron emission tomography (PET) stress tests (nitrogen-13 labeled ammonia or rubidium-82). Patients with LVEF\\ 50%, prior abnormal myocardial perfusion study, history of coronary artery bypass surgery or heart transplantation, were excluded. Regional and global rest and stress myocardial blood flow (MBF) (ml min g) was quantified, and regional and global myocardial flow reserve (MFR) was calculated as a ratio of stress to rest MBF. Over a median follow-up of 7.8 years there were 51 deaths and 63 major adverse cardiovascular events (MACE-composite of CV death or hospitalization for nonfatal MI, cerebral vascular accident, late coronary revascularization, or heart failure). The cohort (median age-65 years, 80% female) had a high prevalence of coronary risk factors including hypertension (75.3%), dyslipidemia (56.6%), obesity (39.9%), and diabetes mellitus (30.3%). Patients with SLE were younger, more likely to be females and less likely to have dyslipidemia and diabetes when compared to patients with RA or PsO. The entire group was then categorized into tertiles of increasing MFR: High[2.19, intermediate[1.65, and low\\1.65. There was no variance in the distribution of RA, SLE, and PsO patients across the MFR tertiles. Overall, patients in the lowest tertile demonstrated higher all-cause mortality than in the highest tertile (hazard ratio 2.4 [1.05-5.4], P = 0.038); and likewise, patients in the lowest tertile had a lower MACE-free survival (hazard ratio 3.6 [1.7-7.6], P = 0.001), and these findings remained statistically significant even after adjustment for age, sex, and pretest clinical risk score. Significance: A higher prevalence of CV risk factors has been implicated as an explanation for adverse CV outcomes in patients with systemic inflammatory disease, though these only provide a fractional explanation for the excess risk of myocardial infarction, heart failure, and death in these patients. Abnormal MBF and MFR provide another rationale for the excess CV risk in patients with systemic inflammatory diseases, with worse flow indices being associated with a greater risk of mortality and MACE. Future studies need to account for disease specific markers of severity and also assessment of underlying epicardial stenosis, for a Reprint requests: Saurabh Malhotra, MD MPH FASNC, Division of Cardiology, Cook County Health, Chicago, IL ; saurabh.malhotra@ cookcountyhhs.org J Nucl Cardiol 2021;28:1210–2. 1071-3581/$34.00 Copyright 2021 American Society of Nuclear Cardiology.