Complete Revascularization and Angina-Related Health Status in the ISCHEMIA Trial

Predictors of outcomes after PCI with incomplete revascularization: Impact of CTO and LAD vessel

BACKGROUND

Incomplete revascularization (ICR) after percutaneous coronary intervention (PCI) is associated with mortality and morbidity.

AIM

We sought to investigate whether ICR in the left anterior descending artery (LAD) is worse than ICR of the right coronary artery (RCA) or left circumflex artery (LCX); and whether ICR in patients with a chronic total occlusion (CTO) is worse than in those without.

METHODS

In the RIVER-PCI trial, 2651 patients with ICR after PCI were randomly assigned to ranolazine or placebo. Angiograms were assessed at an independent core laboratory in 2501 patients (94.3%). The primary endpoint was the composite of ischemia-driven revascularization or hospitalization.

RESULTS

A total of 1664 patients (66.5%) had ICR involving the LAD, whereas 837 (33.5%) had ICR limited to the RCA or LCX. At median follow-up of 643 days, the primary endpoint occurred in 26.9% versus 26.5% of patients (adjusted HR [aHR]: 1.03, 95% confidence interval [CI]: 0.88-1.21). A nonrecanalized CTO was present in 854 patients (34.1%) with ICR after PCI. The primary endpoint occurred in 28.6% versus 25.9% of ICR patients with versus without a CTO (aHR: 1.10, 95% CI: 0.94-1.29). However, patients with a CTO had higher rates of ischemia-driven hospitalization without revascularization (aHR: 1.27, 95% CI: 1.04-1.56), heart failure hospitalization (aHR: 2.69, 95% CI: 1.61-4.59) and myocardial infarction (aHR: 1.46, 95% CI: 1.11-1.92) compared with those without.

CONCLUSIONS

The 2-year prognosis was similar in post-PCI patients with ICR whether the LAD was versus was not involved. ICR patients with a CTO had more frequent hospitalizations for ischemia and myocardial infarctions compared with those without.

Outcomes According to Coronary Revascularization Modality in the ISCHEMIA Trial

BACKGROUND

In the ISCHEMIA (International Study of Comparative Health Effectiveness with Medical and Invasive Approaches) trial, the risk of ischemic events was similar in patients with stable coronary artery disease treated with an invasive (INV) strategy of angiography and percutaneous coronary intervention (PCI) or surgical (coronary artery bypass grafting [CABG]) coronary revascularization and a conservative (CON) strategy of initial medical therapy.

OBJECTIVES

The authors analyzed separately the outcomes of INV patients treated with PCI or CABG.

METHODS

Patients without preceding primary outcome events were categorized as INV-PCI or INV-CABG from the time of revascularization. The ISCHEMIA primary outcome (composite of cardiovascular death, protocol-defined myocardial infarction or hospitalization for unstable angina, heart failure, or resuscitated cardiac arrest) was used.

RESULTS

Among INV-CABG patients, primary outcome events occurred in 84 of 512 (16.4%) at a median follow-up of 2.85 years; 48 events (57.1%) occurred within 30 days after CABG, including 40 procedural MIs. Among INV-PCI patients, primary outcome events occurred in 147 of 1,500 (9.8%) at median follow-up of 2.94 years; 31 of which (21.1%) occurred within 30 days after PCI, including 24 procedural MIs. In comparison, 352 of 2,591 CON patients (13.6%) had primary outcome events at a median follow-up of 3.2 years, 22 of which (6.3%) occurred within 30 days of randomization. The adjusted primary outcome risks were higher after both CABG and PCI within 30 days (HR: 16.25 [95% CI: 11.44-23.07] and HR: 2.99 [95% CI: 1.97-4.53]) and lower thereafter (0.63 [95% CI: 0.44-0.89] and 0.66 [95% CI: 0.53-0.82]).

CONCLUSIONS

In ISCHEMIA, early revascularization by PCI and CABG was associated with higher early risks and lower long-term risks of cardiovascular events compared with CON. The early risk was greatest after CABG, owing to protocol-defined procedural MIs.

Coronary flow capacity and survival prediction after revascularization: physiological basis and clinical implications

BACKGROUND AND AIMS

Coronary flow capacity (CFC) is associated with an observed 10-year survival probability for individual patients before and after actual revascularization for comparison to virtual hypothetical ideal complete revascularization.

METHODS

Stress myocardial perfusion (mL/min/g) and coronary flow reserve (CFR) per pixel were quantified in 6979 coronary artery disease (CAD) subjects using Rb-82 positron emission tomography (PET) for CFC maps of artery-specific size-severity abnormalities expressed as percent left ventricle with prospective follow-up to define survival probability per-decade as fraction of 1.0.

RESULTS

Severely reduced CFC in 6979 subjects predicted low survival probability that improved by 42% after revascularization compared with no revascularization for comparable severity (P = .0015). For 283 pre-and-post-procedure PET pairs, severely reduced regional CFC-associated survival probability improved heterogeneously after revascularization (P < .001), more so after bypass surgery than percutaneous coronary interventions (P < .001) but normalized in only 5.7%; non-severe baseline CFC or survival probability did not improve compared with severe CFC (P = .00001). Observed CFC-associated survival probability after actual revascularization was lower than virtual ideal hypothetical complete post-revascularization survival probability due to residual CAD or failed revascularization (P < .001) unrelated to gender or microvascular dysfunction. Severely reduced CFC in 2552 post-revascularization subjects associated with low survival probability also improved after repeat revascularization compared with no repeat procedures (P = .025).

CONCLUSIONS

Severely reduced CFC and associated observed survival probability improved after first and repeat revascularization compared with no revascularization for comparable CFC severity. Non-severe CFC showed no benefit. Discordance between observed actual and virtual hypothetical post-revascularization survival probability revealed residual CAD or failed revascularization.

Machine learning-based prediction of composite risk of cardiovascular events in patients with stable angina pectoris combined with coronary heart disease: development and validation of a clinical prediction model for Chinese patients

Objective: To develop a risk score model for the occurrence of composite cardiovascular events (CVE) in patients with stable angina pectoris (SA) combined with coronary heart disease (CHD) by comparing the modeling effects of various machine learning (ML) algorithms. Methods: In this prospective study, 690 patients with SA combined with CHD attending the Department of Integrative Cardiology, China-Japan Friendship Hospital, from October 2020 to October 2021 were included. The data set was randomly divided into a training group and a testing group in a 7:3 ratio in the per-protocol set (PPS). Model variables were screened using the least absolute shrinkage selection operator (LASSO) regression, univariate analysis, and multifactor logistic regression. Then, nine ML algorithms are integrated to build the model and compare the model effects. Individualized risk assessment was performed using the SHapley Additive exPlanation (SHAP) and nomograms, respectively. The model discrimination was evaluated by receiver operating characteristic curve (ROC), the calibration ability of the model was evaluated by calibration plot, and the clinical applicability of the model was evaluated by decision curve analysis (DCA). This study was approved by the Clinical Research Ethics Committee of China-Japan Friendship Hospital (2020-114-K73). Results: 690 patients were eligible to finish the complete follow-up in the PPS. After LASSO screening and multifactorial logistic regression analysis, physical activity level, taking antiplatelets, Traditional Chinese medicine treatment, Gensini score, Seattle Angina Questionnaire (SAQ)-exercise capacity score, and SAQ-anginal stability score were found to be predictors of the occurrence of CVE. The above predictors are modeled, and a comprehensive comparison of the modeling effectiveness of multiple ML algorithms is performed. The results show that the Light Gradient Boosting Machine (LightGBM) model is the best model, with an area under the curve (AUC) of 0.95 (95% CI = 0.91-1.00) for the test set, Accuracy: 0.90, Sensitivity: 0.87, and Specificity: 0.96. Interpretation of the model using SHAP highlighted the Gensini score as the most important predictor. Based on the multifactorial logistic regression modeling, a nomogram, and online calculators have been developed for clinical applications. Conclusion: We developed the LightGBM optimization model and the multifactor logistic regression model, respectively. The model is interpreted using SHAP and nomogram. This provides an option for early prediction of CVE in patients with SA combined with CHD.

Prediction of left ventricular ejection fraction improvement in patients with ischemic cardiomyopathy after coronary artery bypass grafting based on cardiac magnetic resonance

Background

To investigate the risk factors of left ventricular ejection fraction (LVEF) improvement in patients with ischemic cardiomyopathy (ICM) after coronary artery bypass grafting (CABG), and to construct a model that predicts LVEF improvement.

Methods

A retrospective analysis was performed on 106 ICM patients who received CABG and underwent cardiac magnetic resonance (CMR) at Beijing Anzhen Hospital, Capital Medical University from January 2017 to June 2022. Patients were divided into two groups with improved LVEF and no improved LVEF based on the results of postoperative 6-month transthoracic echocardiography. To analyze the risk factors affecting the LVEF non-improvement after CABG and establish a prediction model.

Results

There was LVEF non-improvement in 30.2% (32/106) of patients. Multivariate analysis showed that the number of transmural scar segments and left ventricular end-systolic volume index (LVESVI) were independent risk factors in LVEF non-improvement after CABG [odds ratio (OR) =2.398, 95% confidence interval (CI): 1.607-3.579, P<0.001; OR =1.036, 95% CI: 1.009-1.063, P=0.008]. The model is built and internally verified. ROC showed that the area under the curve (AUC) was 0.866 (95% CI: 0.792-0.940), calibration curve showed that the probability predicted by the model matched well with the clinical results, and decision curve analysis (DCA) showed that the model had good clinical applicability. During the mean follow-up time of 1.5 years, the incidence of major adverse cardiovascular and cerebrovascular events (MACCE) in the LVEF non-improvement group was higher (5.4% vs. 25.0%, P=0.009), and the NYHA grading was higher (P=0.016), when compared to the LVEF improvement group.

Conclusions

The prediction model based on the number of transmural scar segments and LVESVI has good diagnostic efficacy. Our findings help to identify patients with improved LVEF and thus guide the selection of clinical treatment strategies.

Impact of Complete Revascularization in the ISCHEMIA Trial

BACKGROUND

Anatomic complete revascularization (ACR) and functional complete revascularization (FCR) have been associated with reduced death and myocardial infarction (MI) in some prior studies. The impact of complete revascularization (CR) in patients undergoing an invasive (INV) compared with a conservative (CON) management strategy has not been reported.

OBJECTIVES

Among patients with chronic coronary disease without prior coronary artery bypass grafting randomized to INV vs CON management in the ISCHEMIA (International Study of Comparative Health Effectiveness with Medical and Invasive Approaches) trial, we examined the following: 1) the outcomes of ACR and FCR compared with incomplete revascularization; and 2) the potential impact of achieving CR in all INV patients compared with CON management.

METHODS

ACR and FCR in the INV group were assessed at an independent core laboratory. Multivariable-adjusted outcomes of CR were examined in INV patients. Inverse probability weighted modeling was then performed to estimate the treatment effect had CR been achieved in all INV patients compared with CON management.

RESULTS

ACR and FCR were achieved in 43.4% and 58.4% of 1,824 INV patients. ACR was associated with reduced 4-year rates of cardiovascular death or MI compared with incomplete revascularization. By inverse probability weighted modeling, ACR in all 2,296 INV patients compared with 2,498 CON patients was associated with a lower 4-year rate of cardiovascular death or MI (difference -3.5; 95% CI: -7.2% to 0.0%). In comparison, the event rate difference of cardiovascular death or MI for INV minus CON in the overall ISCHEMIA trial was -2.4%. Results were similar but less pronounced with FCR.

CONCLUSIONS

The outcomes of an INV strategy may be improved if CR (especially ACR) is achieved. (International Study of Comparative Health Effectiveness With Medical and Invasive Approaches [ISCHEMIA]; NCT01471522).