Predictors of outcome in the ISCHEMIA-CKD trial: Anatomy versus ischemia

Relationship Between Severity of Ischemia and Coronary Artery Disease for Different Stress Test Modalities in the ISCHEMIA Trial

BACKGROUND

The relationship between the extent and severity of stress-induced ischemia and the extent and severity of anatomic coronary artery disease (CAD) in patients with obstructive CAD is multifactorial and includes the intensity of stress achieved, type of testing used, presence and extent of prior infarction, collateral blood flow, plaque characteristics, microvascular disease, coronary vasomotor tone, and genetic factors. Among chronic coronary disease participants with site-determined moderate or severe ischemia, we investigated associations between ischemia severity on stress testing and the extent of CAD on coronary computed tomography angiography.

METHODS

Clinically indicated stress testing included nuclear imaging, echocardiography, cardiac magnetic resonance imaging, or nonimaging exercise tolerance test. Among those with preserved renal function who underwent coronary computed tomography angiography, we examined relationships between ischemia and CAD by coronary computed tomography angiography, overall, and by stress test modality, regardless of subsequent randomization. Core laboratories categorized ischemia as severe, moderate, mild, or none, while the extent and severity of anatomic CAD were categorized based on the modified Duke prognostic index.

RESULTS

Among 3601 participants with interpretable stress tests and coronary computed tomography angiography, ischemia severity was weakly associated with CAD extent/severity (r=0.27), with modest variability in strength of association by modality: nuclear (n=1532; r=0.40), echocardiography (n=827; r=0.15), cardiac magnetic resonance imaging (n=108; r=0.31), and exercise tolerance test (n=1134; r=0.18). The extent of infarction on nuclear imaging and echocardiography was weakly associated with CAD extent/severity.

CONCLUSIONS

Overall, ischemia severity on stress testing showed weak to moderate associations with the anatomic extent of CAD in this cohort with moderate or severe ischemia on local interpretation and controlled symptoms.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT01471522.

Emerging Evidence on Coronary Heart Disease Screening in Kidney and Liver Transplantation Candidates: A Scientific Statement From the American Heart Association: Endorsed by the American Society of Transplantation

Coronary heart disease is an important source of mortality and morbidity among kidney transplantation and liver transplantation candidates and recipients and is driven by traditional and nontraditional risk factors related to end-stage organ disease. In this scientific statement, we review evidence from the past decade related to coronary heart disease screening and management for kidney and liver transplantation candidates. Coronary heart disease screening in asymptomatic kidney and liver transplantation candidates has not been demonstrated to improve outcomes but is common in practice. Risk stratification algorithms based on the presence or absence of clinical risk factors and physical performance have been proposed, but a high proportion of candidates still meet criteria for screening tests. We suggest new approaches to pretransplantation evaluation grounded on the presence or absence of known coronary heart disease and cardiac symptoms and emphasize multidisciplinary engagement, including involvement of a dedicated cardiologist. Noninvasive functional screening methods such as stress echocardiography and myocardial perfusion scintigraphy have limited accuracy, and newer noninvasive modalities, especially cardiac computed tomography-based tests, are promising alternatives. Emerging evidence such as results of the 2020 International Study of Comparative Health Effectiveness With Medical and Invasive Approaches-Chronic Kidney Disease trial emphasizes the vital importance of guideline-directed medical therapy in managing diagnosed coronary heart disease and further questions the value of revascularization among asymptomatic kidney transplantation candidates. Optimizing strategies to disseminate and implement best practices for medical management in the broader end-stage organ disease population should be prioritized to improve cardiovascular outcomes in these populations.

Ischemia Trial: Does the Cardiology Community Need to Pivot or Continue Current Practices?

PURPOSE OF REVIEW

For decades, the standard of care for stable ischemic heart disease (SIHD) has been an ischemia-centric approach based on largely observational data suggesting a survival benefit of revascularization in patients with moderate-or-severe ischemia. In this article, we will objectively review the evolution of the ischemia paradigm, the trial evidence comparing revascularization to medical therapy in SIHD, and what contemporary practice should be in 2022.

RECENT FINDINGS

Randomized trials, including COURAGE and, most recently, the ISCHEMIA trial, have shown no reduction in "hard outcomes" like death and myocardial infarction (MI) in SIHD compared to medical therapy. The trial excluded high-risk patients with left main disease, low ejection fraction (EF) < 35%, and severe unacceptable angina. Irrespective of the severity of ischemia and the extent of coronary artery disease (CAD), revascularization did not offer any prognostic advantage over medical therapy. On the other hand, there was a durable improvement in symptoms. While there are many caveats to the ISCHEMIA trial, the overall strengths of the trial outweigh these limitations. The findings of ISCHEMIA are consistent with previous trials. It is time for the cardiology community to pivot towards medical therapy as the initial step for most patients with SIHD. Physicians should have the "COURAGE" to embrace "ISCHEMIA" and be comfortable with treating ischemia medically.