Prognostic Value of Myocardial Perfusion Analysis in Patients with Coronary Artery Disease: A Meta-Analysis

Long-term prognostic value of stress myocardial perfusion echocardiography in patients with coronary artery disease: a meta-analysis

AIMS

To evaluate the prognostic value of myocardial perfusion (MP) imaging during contrast stress echocardiography (cSE) in patients with known or suspected coronary artery disease (CAD).

METHODS AND RESULTS

A search in PubMed, Embase databases, and the Cochrane library was conducted through May 2019. The Cochran Q statistic and the I2 statistic were used to assess heterogeneity, and the results were analysed by RevMan V5.3 and Stata V15.1 software. Twelve studies (seven dipyridamole and five exercise/dobutamine) without evidence of patient overlap (same institution publishing results over a similar time period) enrolling 5953 subjects (47% female, 8-80 months of follow-up) were included in the analysis. In all studies, total adverse cardiovascular events were defined as either cardiac death, non-fatal myocardial infarction (NFMI), or need for urgent revascularization. Hazard ratios (HRs) revealed that a MP abnormality [pooled HR 4.75; 95% confidence interval (CI) 2.47-9.14] was a higher independent predictor of total events than abnormal wall motion (WM, pooled HR 2.39; 95% CI 1.58-3.61) and resting left ventricular ejection fraction (LVEF, pooled HR 1.92; 95% CI 1.44-2.55) with significant subgroup differences (P = 0.002 compared with abnormal WM and 0.01 compared with abnormal LVEF). Abnormal MP was associated with higher risks for death [Risk ratio (RR) 5.24; 95% CI 2.91-9.43], NFMI (RR 3.09; 95% CI 1.84-5.21), and need for coronary revascularization (RR 16.44; 95% CI 6.14-43.99).

CONCLUSION

MP analysis during stress echocardiography is an effective prognostic tool in patients with known or suspected CAD and provides incremental value over LVEF and WM in predicting clinical outcomes.

Myocardial infarction triggers cardioprotective antigen-specific T helper cell responses

T cell autoreactivity is a hallmark of autoimmune diseases but can also benefit self-maintenance and foster tissue repair. Herein, we investigated whether heart-specific T cells exert salutary or detrimental effects in the context of myocardial infarction (MI), the leading cause of death worldwide. After screening more than 150 class-II-restricted epitopes, we found that myosin heavy chain alpha (MYHCA) was a dominant cardiac antigen triggering post-MI CD4+ T cell activation in mice. Transferred MYHCA614-629-specific CD4+ T (TCR-M) cells selectively accumulated in the myocardium and mediastinal lymph nodes (med-LN) of infarcted mice, acquired a Treg phenotype with a distinct pro-healing gene expression profile, and mediated cardioprotection. Myocardial Treg cells were also detected in autopsies from patients who suffered a MI. Noninvasive PET/CT imaging using a CXCR4 radioligand revealed enlarged med-LNs with increased cellularity in MI-patients. Notably, the med-LN alterations observed in MI patients correlated with the infarct size and cardiac function. Taken together, the results obtained in our study provide evidence showing that MI-context induces pro-healing T cell autoimmunity in mice and confirms the existence of an analogous heart/med-LN/T cell axis in MI patients.

Clinical practice of contrast echocardiography: recommendation by the European Association of Cardiovascular Imaging (EACVI) 2017

Contrast echocardiography is widely used in cardiology. It is applied to improve image quality, reader confidence and reproducibility both for assessing left ventricular (LV) structure and function at rest and for assessing global and regional function in stress echocardiography. The use of contrast in echocardiography has now extended beyond cardiac structure and function assessment to evaluation of perfusion both of the myocardium and of the intracardiac structures. Safety of contrast agents have now been addressed in large patient population and these studies clearly established its excellent safety profile. This document, based on clinical trials, randomized and multicentre studies and published clinical experience, has established clear recommendations for the use of contrast in various clinical conditions with evidence-based protocols.