Quantitative assessment of myocardial blush grade in patients with coronary artery disease and in cardiac transplant recipients

Arginine Vasopressin Plays a Role in Microvascular Dysfunction After ST-Elevation Myocardial Infarction

Background Coronary microvascular dysfunction (CMD) predicts mortality after ST-elevation-myocardial infarction (STEMI). Arginine vasopressin (AVP) may be implicated, but data in humans are lacking, and no study has investigated the link between arginine vasopressin and invasive measures of CMD. Methods and Results We invasively assessed CMD in 55 patients with STEMI treated with primary percutaneous coronary intervention (PPCI), by measuring the index of microcirculatory resistance after PPCI. In a separate group of 45 patients with STEMI/PPCI, recruited for a clinical trial, we measured infarct size and microvascular obstruction with cardiac magnetic resonance (CMR) imaging at 1 week and 12 weeks post-STEMI. Serum copeptin was measured at 4 time points before and after PPCI in all patients with STEMI. Plasma copeptin levels fell from 92.5 pmol/L before reperfusion to 6.4 pmol/L at 24 hours. Copeptin inversely correlated with diastolic, but not systolic, blood pressure (r=-0.431, P=0.001), suggesting it is released in response to myocardial ischemia. Persistently raised copeptin at 24 hours was correlated with higher index of microcirculatory resistance (r=0.372, P=0.011). Patients with microvascular obstruction on early CMR imaging showed a trend toward higher admission copeptin, which was not statistically significant. Copeptin levels were not associated with infarct size on either early or late CMR. Conclusions Patients with CMD after STEMI have persistently elevated copeptin at 24 hours, suggesting arginine vasopressin may contribute to microvascular dysfunction. Arginine vasopressin receptor antagonists may represent a novel therapeutic option in patients with STEMI and CMD.

Myocardial blush grade: a determinant of left ventricular ejection fraction and adverse outcomes in STEMI

BACKGROUND AND AIMS

Despite restoration of blood flow, subtle microvascular obstruction can occur. This obstruction can be graded using myocardial blush grade. We aimed to investigate the role of myocardial blush grade in ejection fraction and adverse outcomes, after percutaneous intervention.

METHODS

A prospective, observational study was conducted at our institute with a calculated sample size. Variables such as age, gender, and ejection fraction were noted before the intervention. The patients were followed for 3 months to determine the outcomes. The data was analyzed using IBM SPSS software version 26.0. P-value of less than 0.05 was considered significant for the statistical tests.

RESULTS

There were 74 male and 36 female participants in the study. The mean age was 52.20 ± 10.02 years. The most common adverse outcome was heart failure (18%). There was a significant Pearson's correlation between myocardial blush grade and improvement in ejection fraction (p < 0.05). Improvement in myocardial blush grade was significantly related to a decrease in adverse outcomes (p < 0.05). Regression analysis proved myocardial blush grade and diabetes status as independent predictors of percentage increase in ejection fraction (p < 0.05).

CONCLUSION

High myocardial blush grade is one of the independent predictors of better outcomes in ST-elevation myocardial infarction.

Transplant allograft vasculopathy: Role of multimodality imaging in surveillance and diagnosis

Cardiac allograft vasculopathy (CAV) is a challenging long-term complication of cardiac transplantation and remains a leading long-term cause of graft failure, re-transplantation, and death. CAV is an inflammatory vasculopathy distinct from traditional atherosclerotic coronary artery disease. Historically, the surveillance and diagnosis of CAV has been dependent on serial invasive coronary angiography with intravascular imaging. Although commonly practiced, angiography is not without significant limitations. Technological advances have provided sophisticated imaging techniques for CAV assessment. It is now possible to assess the vascular lumen, vessel wall characteristics, absolute blood flow, perfusion reserve, myocardial contractile function, and myocardial metabolism and injury in a noninvasive, expeditious manner with little risk. The current article will review key imaging modalities for the surveillance, diagnosis, and prognosis of CAV and discuss coronary physiology of transplanted hearts with emphasis on the clinical implications for provocative and vasodilator stress testing.