To the Editor: As a consequence of the coronavirus disease 2019 (COVID-19) pandemic, hospitals have had to reconfigure the role for cardiac intensive care unit (CICU) staffing to meet the health care needs of their communities.1 Interventional cardiologists (ICs), among other specialists, have been redeployed in the CICU to take care of a primary respiratory illness with multiorgan failure. These physicians are required to be skilled with ventilator management, end-organ injury, fluid and electrolyte balance, and end-of-life care. Even before the COVID-19 pandemic, the CICU had noted dramatic shifts in its landscape and started to resemble a medical intensive care unit population with a primary cardiac illness complicated by multiorgan involvement and intensive care needs. This contrast has been further amplified by the ongoing pandemic.

Acute myocardial infarction with cardiogenic shock (AMI-CS) is associated with high mortality and morbidity despite advancements in cardiovascular care. AMI-CS is associated with multiorgan failure of non-cardiac organ systems. Acute kidney injury (AKI) is frequently seen in patients with AMI-CS and is associated with worse mortality and outcomes compared to those without. The pathogenesis of AMI-CS associated with AKI may involve more factors than previously understood. Early use of renal replacement therapies, management of comorbid conditions and judicious fluid administration may help improve outcomes. In this review, we seek to address the etiology, pathophysiology, management, and outcomes of AKI complicating AMI-CS.

Racial disparities in utilization and outcomes of mechanical circulatory support (MCS) in patients with acute myocardial infarction-cardiogenic shock (AMI-CS) are infrequently studied. This study sought to evaluate racial disparities in the outcomes of MCS in AMI-CS. The National Inpatient Sample (2012–2017) was used to identify adult AMI-CS admissions receiving MCS support. MCS devices were classified as intra-aortic balloon pump (IABP), percutaneous left ventricular assist device (pLVAD) or extracorporeal membrane oxygenation (ECMO). Self-reported race was classified as white, black and others. Outcomes included in-hospital mortality, hospital length of stay and discharge disposition. During this period, 90,071 admissions were included with white, black and other races constituting 73.6%, 8.3% and 18.1%, respectively. Compared to white and other races, black race admissions were on average younger, female, with greater comorbidities, and non-cardiac organ failure (all p < 0.001). Compared to the white race (31.3%), in-hospital mortality was comparable in black (31.4%; adjusted odds ratio (aOR) 0.98 (95% confidence interval (CI) 0.93–1.05); p = 0.60) and other (30.2%; aOR 0.96 (95% CI 0.92–1.01); p = 0.10). Higher in-hospital mortality was noted in non-white races with concomitant cardiac arrest, and those receiving ECMO support. Black admissions had longer lengths of hospital stay (12.1 ± 14.2, 10.3 ± 11.2, 10.9 ± 1.2 days) and transferred less often (12.6%, 14.2%, 13.9%) compared to white and other races (both p < 0.001). In conclusion, this study of AMI-CS admissions receiving MCS devices did not identify racial disparities in in-hospital mortality. Black admissions had longer hospital stay and were transferred less often. Further evaluation with granular data including angiographic and hemodynamic parameters is essential to rule out racial differences.

The planning of revascularization strategy for multivessel coronary artery disease (CAD) in nondiabetic patients is optimally made through considering the goals of improving survival and/or relieving symptoms. Existing clinical practice guidelines and appropriate use criteria (1–3) state that in nondiabetic patients with multivessel CAD and stable ischemic heart disease (SIHD), either coronary artery bypass grafting (CABG) or percutaneous coronary intervention (PCI) with drug-eluting stents may be used for those with low SYNTAX (Synergy Between PCI With Taxus and Cardiac Surgery) scores, but CABG is preferred for those with intermediate or high SYNTAX scores. In the overall SYNTAX population (4–6), the rates of death and stroke were similar, but the risk of myocardial infarction (MI) and repeat revascularization were higher in PCI-treated patients. At 5-year follow-up, the rates of death/stroke/MI are 8.0% lower, and the rate of repeat revascularization is 12.8% lower in CABG-treated patients. In the low SYNTAX score tertile, these trends are not significantly different, but they are in the intermediate and high SYNTAX score subsets. When considering only survival in the 3 tertiles, there was a 0.9%, 6.7%, and 9.0% difference over 5 years, an average of 0.2% to 1.8% per year. Yet, PCI is more often performed in multivessel CAD patients, despite the guidelines and clinical evidence. Can this apparent divergence from the evidence base be supported? Drs. Weintraub and Tcheng and colleagues were asked to defend or critique the current guidelines.

Background Genome-wide association studies have identified multiple variants associating with coronary artery disease (CAD) and myocardial infarction (MI). Whether a combined genetic risk score (GRS) is associated with prevalent and incident MI in high risk subjects remains to be established. Methods and Results In subjects undergoing cardiac catheterization (n=2597) we identified cases with a history of MI onset at age <70 years and controls ≥70 years old without prior MI, and followed them for incident MI and death. Genotyping was performed for 11 established CAD/MI variants and a GRS calculated based on average number of risk alleles carried at each locus weighted by effect size. Replication of association findings was sought in an independent angiographic cohort (n=2702). The GRS was significantly associated with prevalent MI, occurring before age 70 years, compared to older controls (≥70 years) with no history of MI (p<0.001). This association was successfully replicated in a second cohort yielding a pooled p value of <0.001. The GRS modestly improved the c-statistic in models of prevalent MI with traditional risk factors. However, the association was not statistically significant when elderly controls without MI but with stable angiographic CAD were examined (pooled p=0.11). Finally, during a median 2.5 year follow-up, only a non-significant trend was noted between the GRS and incident events, which was also not significant in the replication cohort. Conclusions A GRS of 11 CAD/MI variants is associated with prevalent MI but not near term incident adverse events in two independent angiographic cohorts. These findings have implications for understanding the clinical utility of genetic risk scores for secondary as opposed to primary risk prediction.

Background Multiple scoring systems have been devised to quantify angiographic coronary artery disease (CAD) burden, but it is unclear how these scores relate to each other and which scores are most accurate. The aim of this study was to compare coronary angiographic scoring systems 1) with each other and 2) with intravascular ultrasound (IVUS) derived plaque burden in a population undergoing angiographic evaluation for CAD. Methods Coronary angiographic data from 3600 patients was scored using 10 commonly used angiographic scoring systems and inter-score correlations were calculated. In a subset of 50 patients, plaque burden and plaque area in the left anterior descending coronary artery was quantified using IVUS and correlated with angiographic scores. Results All angiographic scores correlated with each other (range for Spearman coefficient (ρ): 0.79-0.98, p<0.0001); the two most widely used scores, Gensini and CASS-70, had a ρ = 0.90, p<0.0001. All scores correlated significantly with average plaque burden and plaque area by IVUS (range ρ: 0.56-0.78, p<0.0001 and 0.43-0.62, p<0.01, respectively). The CASS-50 score had the strongest correlation (ρ: 0.78 and 0.62, p<0.0001) and the Duke Jeopardy score the weakest correlation (ρ: 0.56 and 0.43, p<0.01) with plaque burden and area, respectively. Conclusions Angiographic scoring systems are strongly correlated with each other and with atherosclerotic plaque burden. Scoring systems therefore appear to be a valid estimate of CAD plaque burden.

We investigated whether local hemodynamics were associated with sites of plaque erosion and hypothesized that patients with plaque erosion have locally elevated WSS magnitude in regions where erosion has occurred. We generated 3D, patient-specific models of coronary arteries from biplane angiographic images in 3 human patients with plaque erosion diagnosed by optical coherence tomography. Using computational fluid dynamics, we simulated pulsatile blood flow and calculated both wall shear stress (WSS) and oscillatory shear index (OSI). We also investigated anatomic features of plaque erosion sites by examining branching and local curvature in X-ray angiograms of barium-perfused autopsy hearts. Neither high nor low magnitudes of mean WSS were associated with sites of plaque erosion. OSI and local curvature were also not associated with erosion. Anatomically, 8 of 13 hearts had a nearby bifurcation upstream of the site of plaque erosion. This study provides preliminary evidence that neither hemodynamics nor anatomy are predictors of plaque erosion, based upon a very unique dataset. Our sample sizes are small, but this dataset suggests that high magnitudes of WSS, one potential mechanism for inducing plaque erosion, are not necessary for erosion to occur.