Daily Cardiology Research Analysis
Three impactful cardiology studies stand out today: a Medicare cohort shows that CABG with surgical AVR outperforms PCI with TAVR for 5-year outcomes in patients with concomitant CAD, despite lower procedural mortality with PCI+TAVR. A new STS Intermacs 90-day mortality risk model for durable LVADs demonstrates solid discrimination and calibration, enabling center-level quality benchmarking. A meta-analysis suggests SGLT2 inhibitors are associated with markedly better survival and fewer events i
Summary
Three impactful cardiology studies stand out today: a Medicare cohort shows that CABG with surgical AVR outperforms PCI with TAVR for 5-year outcomes in patients with concomitant CAD, despite lower procedural mortality with PCI+TAVR. A new STS Intermacs 90-day mortality risk model for durable LVADs demonstrates solid discrimination and calibration, enabling center-level quality benchmarking. A meta-analysis suggests SGLT2 inhibitors are associated with markedly better survival and fewer events in transthyretin amyloid cardiomyopathy.
Research Themes
- Comparative effectiveness in structural heart disease (PCI+TAVR vs CABG+SAVR)
- Risk prediction and quality benchmarking in durable LVAD therapy
- Therapeutic repurposing: SGLT2 inhibitors in transthyretin amyloid cardiomyopathy
Selected Articles
1. Transcatheter vs Surgical Aortic Valve Replacement in Medicare Beneficiaries With Aortic Stenosis and Coronary Artery Disease.
In a 37,822-patient Medicare cohort with AS and CAD, PCI+TAVR had lower procedural mortality but higher vascular complications and pacemaker use. After risk adjustment, CABG+SAVR yielded superior 5-year composite outcomes (stroke/MI/reintervention/death) than PCI+TAVR, with additional benefit of arterial conduits in single-vessel CAD.
Impact: This large, rigorously adjusted national analysis directly informs strategic decision-making for patients with AS and concomitant CAD, challenging the trend toward PCI+TAVR by demonstrating superior long-term outcomes with CABG+SAVR.
Clinical Implications: For AS with significant CAD, heart teams should weigh lower procedural risk of PCI+TAVR against superior 5-year outcomes with CABG+SAVR; surgical strategies using arterial conduits may further enhance benefit in single-vessel CAD. Shared decision-making should incorporate long-term prognosis, revascularization completeness, and pacemaker risk.
Key Findings
- PCI+TAVR had lower procedural mortality than CABG+SAVR (1.1% vs 3.6%; OR 0.29; P<.001).
- PCI+TAVR had higher vascular complications (OR 6.02; P<.001) and new permanent pacemaker implantation (OR 1.92; P<.001).
- The 5-year composite outcome (stroke, MI, valve reintervention, or death) favored CABG+SAVR (20.4% vs 14.2%; OR 1.44; P<.001).
- Use of arterial conduits in CABG+SAVR was beneficial in single-vessel CAD.
Methodological Strengths
- Very large national cohort with robust doubly robust adjustment (IPW, multilevel models, competing-risk analyses)
- Clinically relevant 5-year composite endpoint and prespecified subgroup analyses
Limitations
- Observational design with potential residual confounding and selection bias
- Claims-based data limit anatomical and procedural granularity (lesion complexity, completeness of revascularization)
Future Directions: Prospective comparative trials or pragmatic registries integrating anatomical complexity, physiologic assessments, and patient-centered outcomes could refine selection algorithms; cost-effectiveness analyses across risk strata are warranted.
BACKGROUND: As percutaneous therapeutic options expand, the optimal management of severe aortic stenosis (AS) and concomitant coronary artery disease (CAD) is being questioned between coronary artery bypass grafting with surgical aortic valve replacement (CABG+SAVR) and percutaneous coronary intervention with transcatheter aortic valve replacement (PCI+TAVR). This study sought to compare perioperative and longitudinal risk-adjusted outcomes between patients undergoing CABG+SAVR and patients undergoing PCI+TAVR. METHODS: Using the Centers for Medicare & Medicaid Services inpatient claims database, the study evaluated all patient aged 65 years and older with AS and CAD who were undergoing CABG+SAVR or PCI+TAVR (from 2018 to 2022). Comorbidities and frailty were accounted for using validated metrics with doubly robust risk adjustment using inverse probability weighting, multilevel regression, and competing-risk time to event analyses. The primary end point was a 5-year composite of stroke, myocardial infarction (MI), valve reintervention, or death. RESULTS: A total of 37,822 patients formed the study cohort (PCI+TAVR, n = 17,413; CABG+SAVR, n = 20,409). Accounting for age, comorbidities, frailty, and number of vessels revascularized, PCI+TAVR was associated with lower procedural mortality (1.1% vs 3.6%; odds ratio [OR], 0.29; P <.001) but higher vascular complications (OR, 6.02; P <.001) and new permanent pacemaker (OR, 1.92; P <.001). However, the longitudinal 5-year primary end point favored CABG+SAVR (20.4% vs 14.2%; OR, 1.44, P <.001). Subgroup analyses demonstrated a benefit in the use of arterial conduit in CABG+;AVR in patients with single-vessel CAD. CONCLUSIONS: Among Medicare beneficiaries with severe AS and CAD, CABG+SAVR was associated with higher procedural mortality than PCI+TAVR but lower 5-year risk-adjusted stroke, MI, valve reintervention, and death.
2. Sodium-glucose cotransporter 2 inhibitors and outcomes in transthyretin amyloid cardiomyopathy: Systematic review and meta-analysis.
Across five observational studies (n=9,766), SGLT2 inhibitors in ATTR-CM were associated with substantially lower all-cause and CV mortality, fewer MACE and HF hospitalizations, and reduced arrhythmias including AF and ventricular tachycardia. Findings suggest a promising adjunct therapy pending randomized confirmation.
Impact: Addresses a major therapeutic gap in ATTR-CM with broad availability drugs and signals multi-domain benefits. High clinical interest and strong impetus for confirmatory RCTs.
Clinical Implications: In ATTR-CM with heart failure, SGLT2 inhibitors may be considered as adjuncts to standard care (e.g., diuretics, tafamidis when indicated), recognizing the observational evidence base and need for individualized risk-benefit assessment.
Key Findings
- All-cause mortality reduced with SGLT2i (HR 0.54, 95% CI 0.44–0.66).
- Cardiovascular mortality reduced (HR 0.39, 95% CI 0.23–0.65).
- MACE reduced (HR 0.71, 95% CI 0.61–0.83) and HF hospitalization reduced (HR 0.63, 95% CI 0.52–0.77).
- Arrhythmia odds reduced (OR 0.73), including AF (OR 0.75), VT (OR 0.72), and sudden cardiac arrest (OR 0.71).
Methodological Strengths
- Comprehensive database search with independent dual screening and extraction
- Random-effects meta-analysis across multiple clinically relevant endpoints
Limitations
- Predominantly observational, propensity-matched data subject to residual confounding
- Limited granularity on ATTR genotype/phenotype, tafamidis co-therapy, and dosing
Future Directions: Design and execution of adequately powered, long-term randomized trials of SGLT2i in ATTR-CM, with stratification by genotype (wild-type vs variant), amyloid burden, and background therapies.
BACKGROUND: Transthyretin amyloid cardiomyopathy (ATTR-CM) commonly leads to heart failure but has traditionally been an exclusion criterion in randomized clinical trials (RCTs) of sodium-glucose cotransporter 2 inhibitors (SGLT2i); therefore, the effects of these drugs in this population remain undocumented. In light of recent studies, this meta-analysis aimed to investigate the effect of SGLT2i on the prognosis of patients with ATTR-CM. METHODS: A comprehensive search of Medline, Scopus, and the Cochrane Library was conducted up to November 17, 2024. Study selection, data extraction and quality assessment were carried out independently by two investigators. Associations of SGLT2i with outcomes were pooled using random-effects meta-analyses. RESULTS: A total of five studies (9766 participants, 4 propensity score-matched) were included. The use of SGLT2i was associated with significant reductions in all-cause mortality [hazard ratio (HR) .54, 95% confidence interval (CI) .44-.66], cardiovascular mortality (HR .39, 95% CI .23-.65), major adverse cardiovascular events (HR .71, 95% CI .61-.83), and heart failure hospitalizations (HFHs) (HR .63, 95% CI .52-.77) compared to non-use. The odds of cardiac arrhythmias were significantly lower among SGLT2i users compared to non-users [odds ratio (OR) .73, 95% CI .65-.83]. Specifically, SGLT2i use was associated with significant reductions in the odds of atrial fibrillation (AF) (OR .75, 95% CI .62-.91), ventricular tachycardia (OR .72, 95% CI .59-.88), and sudden cardiac arrest (OR .71, 95% CI .50-.99). CONCLUSIONS: The use of SGLT2is may be associated with a more favourable prognosis in patients with ATTR-CM. Adequately powered, long-term RCTs are required to validate the available observational evidence.
3. The Society of Thoracic Surgeons National Intermacs Database Risk Model for Durable Left Ventricular Assist Device Implantation.
Using 11,342 STS Intermacs LVAD implants (2019–2023), a 90-day mortality model achieved AUC ~0.71 with good calibration. The model supports candidate selection, benchmarking via center-level O/E ratios, and quality improvement, while noting risk overestimation at high predicted probabilities (>0.4).
Impact: Provides a contemporary, validated prognostic tool for LVAD programs with immediate utility in clinical decision-making and center performance assessment.
Clinical Implications: Integrate the model into preimplant evaluation to quantify 90-day mortality risk, guide consent and optimization, and identify outlier centers for targeted quality improvement.
Key Findings
- Derivation (n=6,775) and validation (n=4,567) cohorts yielded AUC 0.714 and 0.707, respectively, with good calibration (Brier 0.08/0.07).
- Model tended to overestimate risk at predicted probabilities >0.4.
- Center-level O/E analysis identified 12.5% centers worse-than-expected and 8.0% better-than-expected mortality (P<.05).
Methodological Strengths
- Large national registry with temporal split for derivation/validation
- Transparent performance reporting (AUC, Brier, calibration plots) and center-level benchmarking
Limitations
- Moderate discrimination (AUC ~0.71) and overestimation at high predicted risk
- Registry constraints (missingness, unmeasured confounders) and generalizability outside STS centers
Future Directions: Incorporate granular hemodynamics, frailty, and social determinants; explore machine learning recalibration and dynamic updating; link to patient-reported outcomes and cost metrics.
BACKGROUND: Statistical risk models for durable left ventricular assist device (LVAD) implantation inform candidate selection, quality improvement, and evaluation of provider performance. This study developed a 90-day mortality risk model using The Society of Thoracic Surgeons National Intermacs Database (STS Intermacs). METHODS: STS Intermacs was queried for primary durable LVAD implants from January 2019 to September 2023. Multivariable logistic regression was used to derive a model based on preimplant risk factors by using derivation (2019-2021 implants) and validation (2022-2023 implants) cohorts. Model performance (derivation and validation cohorts) was assessed using C-statistics, Brier scores, and calibration plots. A refined model (all patients) was generated to calculate observed-to-expected (O/E; 95% CI) ratios for each center. RESULTS: The study population consisted of 11,342 patients from 2019 to 2023 who were sequentially divided in time into derivation (n = 6775) and validation (n = 4567) cohorts. Ninety-day mortality was 8.0% (9.2% in the derivation cohort vs 7.4% in the validation cohort; P = .001). Logistic regression applied to derivation and validation cohorts produced similar discrimination (area under the curve [AUC], 0.714 [95% CI, 0.69-0.74]; and AUC, 0.707; [95% CI, 0.67-0.72], respectively) and calibration (Brier score, .08 vs .07), with overestimation of risk among patients with a predicted risk >0.4. The O/E analysis identified 22 (12.5%) centers with worse than expected mortality with a 95% CI >1.0 and 14 centers (8.0%) with better than expected mortality with a 95% CI <1.0 (all P < .05). CONCLUSIONS: The STS Intermacs risk model demonstrated satisfactory discrimination and calibration. This tool may be used to inform candidate selection, facilitate quality improvement, and assess provider performance.