Daily Cardiology Research Analysis
Three impactful cardiology studies stand out today: a PROSPERO-registered meta-analysis shows purified EPA reduces cardiovascular mortality more than mixed EPA/DHA; a large, blinded RCT finds no outcome differences between restrictive vs liberal oxygenation during CPB-assisted cardiac surgery; and a propensity-matched TAVR registry clarifies trade-offs between self-expanding and balloon-expandable valves in heavily calcified cusps with comparable 5-year mortality.
Summary
Three impactful cardiology studies stand out today: a PROSPERO-registered meta-analysis shows purified EPA reduces cardiovascular mortality more than mixed EPA/DHA; a large, blinded RCT finds no outcome differences between restrictive vs liberal oxygenation during CPB-assisted cardiac surgery; and a propensity-matched TAVR registry clarifies trade-offs between self-expanding and balloon-expandable valves in heavily calcified cusps with comparable 5-year mortality.
Research Themes
- Omega-3 therapy differentiation (EPA vs EPA/DHA) and cardiovascular mortality
- Perioperative oxygenation strategy in CPB-assisted cardiac surgery
- Device selection in TAVR with excessive leaflet calcification
Selected Articles
1. Effects of Eicosapentaenoic Acid vs Eicosapentaenoic/Docosahexaenoic Acids on Cardiovascular Mortality: Meta-Analysis of Clinical Trials.
Across 16 RCTs (127,771 participants; median follow-up 3.7 years), purified EPA significantly reduced cardiovascular mortality (HR 0.79), whereas EPA/DHA showed a smaller effect (HR 0.92). The analysis supports preferential use of EPA where indicated for cardiovascular risk reduction.
Impact: Clarifies divergent mortality effects between EPA and EPA/DHA using a registered, comprehensive meta-analysis of RCTs, directly informing lipid-lowering adjunct therapy choices.
Clinical Implications: When considering omega-3 therapy as an adjunct to statins, purified EPA should be prioritized for indications supported by evidence of cardiovascular mortality reduction, while recognizing that EPA/DHA confers a smaller benefit.
Key Findings
- Included 16 RCTs with 127,771 patients (41% women; mean age 64 ± 5 years).
- Purified EPA reduced cardiovascular-attributable mortality vs standard therapy (HR 0.79; 95% CI 0.67-0.94; P=0.006).
- EPA/DHA showed a smaller mortality effect (HR 0.92; 95% CI 0.84-1.00; P=0.044).
- Median follow-up was 3.7 years (IQR 2.7-5.0 years).
Methodological Strengths
- Prespecified protocol registered in PROSPERO.
- Random-effects meta-analysis of randomized clinical trials with large aggregate sample size.
Limitations
- Comparisons between EPA and EPA/DHA are indirect across different trials.
- Heterogeneity sources and safety profiles are not detailed in the abstract.
Future Directions: Head-to-head RCTs of purified EPA vs EPA/DHA and mechanistic studies to explain differential effects; evaluation in diverse populations and contemporary preventive regimens.
BACKGROUND: Purified eicosapentaenoic acid (EPA) and mixed eicosapentaenoic/docosahexaenoic acids (EPA/DHA) are omega-3 polyunsaturated fatty acids (n-3 PUFAs) of interest for preventing cardiovascular disease (CVD) as adjunct to statins. Randomized clinical trial (RCT) evidence continues to emerge, including data from the RESPECT-EPA (Randomized Trial for Evaluation in Secondary Prevention Efficacy of Combination Therapy-Statin and Eicosapentaenoic Acid) trial, but n-3 PUFAs' roles in prevention remains controversial. OBJECTIVES: The objective of the study was to assess the efficacy of EPA vs EPA/DHA compared to the standard preventive therapy across published RCTs investigating the use of n-3 PUFAs for primary or secondary prevention of CVD. METHODS: Following a prespecified protocol registered in the PROSPERO database (CRD42023390587), we identified RCTs reporting CVD-attributable mortality in patients randomized to EPA, EPA/DHA, or a standard preventive therapy for primary or secondary CVD prevention. We used random effects meta-analysis to estimate pooled HRs of CVD-attributable mortality achieved with EPA or EPA/DHA relative to the standard preventive therapy. RESULTS: Sixteen RCTs met the inclusion criteria, representing 127,771 patients in total (41% women, mean age 64 ± 5 years). Median follow-up was 3.7 years (IQR: 2.7-5.0 years). Compared to the standard preventive therapy, CVD-attributable mortality was significantly reduced with purified EPA (HR: 0.79 [95% CI: 0.67-0.94]; P = 0.006); this effect was less for EPA/DHA (HR: 0.92 [95% CI: 0.84-1.00]; P = 0.044). CONCLUSIONS: EPA lowered incident CVD-attributable mortality in RCTs investigating its use for primary or secondary CVD prevention. Relative to EPA, benefits reported with EPA/DHA were attenuated. Although more work is needed to understand these differences, EPA should preferentially be used in cardiovascular conditions for which it is indicated.
2. Restrictive versus liberal oxygenation in patients undergoing cardiopulmonary bypass-assisted heart surgery: a randomised controlled trial.
In a single-centre, patient- and assessor-blinded RCT of 1,389 adults undergoing CPB-assisted CABG and/or AVR, restrictive versus liberal intraoperative oxygenation yielded no significant differences in mortality, dialysis-dependent renal failure, stroke, or new/worsening heart failure.
Impact: Provides high-quality randomized evidence that challenges the assumption that stricter oxygen targets improve outcomes in CPB cardiac surgery, supporting flexibility and potential de-escalation of hyperoxia.
Clinical Implications: Perioperative teams can consider either restrictive or liberal oxygenation during CPB without expecting differences in major clinical outcomes, allowing individualized strategies that avoid unnecessary hyperoxia.
Key Findings
- Patient- and assessor-blinded, single-centre randomized trial including 1,389 adults undergoing CPB-assisted CABG and/or AVR.
- No significant differences between restrictive and liberal oxygenation in mortality, dialysis-dependent renal failure, stroke, or new-onset/worsening heart failure.
- Trial registered at ClinicalTrials.gov (NCT02673931).
Methodological Strengths
- Large randomized, blinded design with clinically meaningful endpoints.
- Prospective trial registration.
Limitations
- Single-centre design may limit generalizability.
- The abstract does not report exact oxygen targets or detailed subgroup effects.
Future Directions: Multicentre trials assessing specific oxygen targets, biomarkers of oxidative injury, and longer-term neurocognitive and renal outcomes; evaluation in higher-risk subgroups.
BACKGROUND: Maintaining adequate oxygen delivery during cardiopulmonary bypass (CPB)-assisted cardiac surgery is crucial, but hyperoxia has been suggested to cause organ injury. We compared the effects of restrictive vs liberal oxygenation during CPB and weaning from CPB on clinical outcomes in cardiac surgery. METHODS: We conducted a single-centre, patient- and assessor-blinded randomised trial on adults undergoing CPB-assisted coronary artery bypass grafting, aortic valve replacement, or both. Participants were randomly assigned (1:1) to restrictive (Fio RESULTS: Among 1389 participants (mean age, 67 yr [range, 29-85 yr]; 17% female), randomisation to receive Fio CONCLUSIONS: Among patients undergoing elective or urgent CPB-assisted coronary artery bypass grafting, aortic valve replacement, or both, no significant differences were observed in mortality, dialysis-dependent renal failure, stroke, or new-onset or worsening heart failure between a restrictive oxygenation strategy (Fio CLINICAL TRIAL REGISTRATION: NCT02673931.
3. Self-expanding versus balloon-expandable transcatheter heart valves in patients with excessive aortic valve cusp calcification.
In a propensity-matched cohort of TAVR patients with excessive leaflet calcification (271 matched pairs from 1,345), BEV had more annular rupture, whereas SEV had lower gradients but more paravalvular regurgitation and pacemaker implantation. Five-year mortality did not differ between devices.
Impact: Provides device-specific trade-offs in a high-risk calcified anatomy, informing procedural planning and patient counseling without a mortality penalty at 5 years.
Clinical Implications: In excessive cusp calcification, BEV may reduce paravalvular regurgitation and pacemaker need but carries higher annular rupture risk; SEV offers lower gradients at the cost of more paravalvular regurgitation and pacemaker implantation. Decisions should weigh anatomy-specific risks and operator experience.
Key Findings
- 1,345 TAVR patients with excessive cusp calcification; 271 propensity-matched pairs.
- Annular rupture: higher with BEV vs SEV (2.2% vs 0%; P=0.030).
- SEV had lower transprosthetic gradient (8.0 vs 11.2 mmHg; P<0.001).
- Paravalvular regurgitation (≥mild) higher with SEV (69.7% vs 58.1%; P=0.008).
- New permanent pacemaker implantation higher with SEV (22.6% vs 15.5%; P=0.001).
- Five-year mortality similar (45.1% vs 50.2%; P=0.173).
Methodological Strengths
- Prospective single-center registry with predefined quantitative calcification threshold and long-term follow-up.
- 1:1 propensity score matching to balance baseline characteristics.
Limitations
- Observational, single-center design; residual confounding cannot be excluded.
- Device generations and techniques spanned many years, potentially introducing temporal bias.
Future Directions: Multicentre randomized or carefully controlled studies in calcified anatomy; integration of CT-based calcification metrics and biomechanical modeling to personalize device selection.
BACKGROUND: Excessive aortic cusp calcification increases the risk of periprocedural complications after transcatheter aortic valve replacement (TAVR). Differences in device performance in patients with excessive calcification may affect long-term clinical outcomes. OBJECTIVES: To compare periprocedural and long-term outcomes between self-expanding (SEV) and balloon-expandable (BEV) prostheses in patients with excess cusp calcification undergoing TAVR. METHODS: Consecutive patients with severe aortic stenosis and aortic valve complex calcium volume ≥235 mm³ (on contrast images with Hounsfield unit threshold of 850) who underwent TAVR with either CoreValve/Evolut SEV or SAPIEN BEV from August 2007 to June 2023 were included from a prospective-single center registry. A 1:1 propensity-matched analysis was performed to account for baseline differences between groups. RESULTS: Among 1,345 patients with excessive cusp calcification undergoing TAVR, 271 matched pairs were identified. Procedural success was achieved in >85% of patients with no difference between groups. Annular rupture occurred more frequently with BEV compared to SEV (2.2% vs 0%, P = .030). SEV had a lower transprosthetic gradient (8.0 mmHg vs 11.2 mmHg, P < .001) but higher rates of mild or greater paravalvular regurgitation (69.7% vs 58.1%, P = .008) and new permanent pacemaker implantation (22.6% vs 15.5%, P = .001). At 5 years, there was no statistically significant difference in mortality between groups (45.1% vs 50.2%, P = .173). CONCLUSIONS: In patients with excessive leaflet calcification undergoing TAVR, BEV had a higher risk of annular rupture, but a lower risk of paravalvular regurgitation, and a lower risk of permanent pacemaker implantation compared to SEV. Mortality was comparable between SEV and BEV throughout 5 years of follow-up. CLINICAL TRIAL REGISTRATION: https://www. CLINICALTRIALS: gov. NCT01368250.