Daily Cardiology Research Analysis

BACKGROUND: A recent phase 3 study of the PET perfusion tracer F-18 flurpiridaz (flurpiridaz) met the primary efficacy endpoint for the detection of CAD, demonstrating statistically higher sensitivity, non-inferior specificity compared to Tc-99m-tetrofosmin/sestamibi SPECT (Tc99m-SPECT) in the general population. This study reports a pre-specified subgroup analysis examining the diagnostic accuracy of flurpiridaz in women. METHODS: Patients with suspected CAD underwent rest-stress flurpiridaz PET and Tc99m-SPECT before invasive coronary angiography in the US, Canada and Europe. The primary endpoint was sensitivity and specificity by 2 expert readers (majority rule between 3 blinded readers) for the diagnosis of significant CAD defined as a stenosis ≥50%. Secondary endpoints included comparison of the diagnostic performance of flurpiridaz PET and Tc99m-SPECT. RESULTS: 188 women were included in the subgroup analysis. Flurpiridaz met the pre-specified primary endpoint of sensitivity [82.9% (95% CI: 71.4, 94.4),p=0.0014] and specificity [72.8% (95%CI: 65.6, 80),p=0.0008]. Flurpiridaz sensitivity was significantly higher than Tc99m-SPECT [82.9% vs.65.9%, difference: 17.1% (-1.5%, 35.6%),p=0.0448] and specificity was non-inferior [72.8% vs. 66%, difference:6.8% (-3.4%, 17.0%) p=0.0004]. Diagnostic certainty was significantly higher for women undergoing flurpiridaz PET compared to Tc99m-SPECT (82.4% v 48.9%). PET perfusion image quality was better than Tc99m-SPECT for rest and pharmacological stress images (p<0.0001). The summed difference score was significantly higher for flurpiridaz (5.3 v 3.5). Radiation exposure was significantly lower for flurpiridaz than same day rest/stress Tc99m-SPECT (6.2 v 11.2 mSv). CONCLUSIONS: This pre-specified secondary analysis of the ARORA study in women, demonstrates high diagnostic accuracy of flurpiridaz PET to detect obstructive CAD. In women, the diagnostic performance of flurpiridaz PET for detection of CAD was significantly higher than with 99mTc-SPECT.

BACKGROUND: Coronary microvascular dysfunction (CMD) is associated with poor prognosis in patients with dilated cardiomyopathy with reduced ejection fraction (DCMrEF). However, its assessment remains challenging in routine clinical practice. This study aims to explore the potential value of Angiography-derived microcirculatory resistance (AMR) in predicting clinical outcomes in DCMrEF patients. METHODS: This multicenter retrospective study included DCMrEF patients (2019-2024) with a 5-year MACE endpoint. AMR was calculated for all major arteries. Its prognostic value was assessed by Kaplan-Meier and multivariate Cox regression. A subgroup analysis was conducted to evaluate the impact of vericiguat treatment on clinical outcomes according to patients' baseline AMR levels. RESULTS: A total of 531 eligible patients with DCMrEF were enrolled in the study, 204 of whom had endpoint events. The optimal AMR cutoffs were >2.295 for the left anterior descending (LAD) artery (AUC=0.776) and left circumflex (LCX) artery, (AUC=0.761), and >2.5 for the right coronary artery (RCA) (AUC=0.745), all with P < 0.001. Patients were then classified into the higher AMR group and the lower AMR group. Kaplan-Meier and multivariate Cox analyses confirmed higher AMR was independently associated with increased MACE risk. LAD-AMR significantly improved risk reclassification over traditional factors (NRI=0.015, IDI=0.051; both P<0.001). Subgroup analysis revealed vericiguat benefitted only patients with elevated AMR. CONCLUSIONS: AMR may be a powerful independent predictor of poor prognosis in DCMrEF patients, with LAD-AMR showing potential for greater predictive value. Vericiguat may represent a potential precision-targeted agent for the high risk of heart failure mediated by microcirculatory dysfunction.

BACKGROUND: Cardiogenic shock (CS) complicating acute myocardial infarction (AMI) carries high mortality. Early revascularisation improves survival, but the effect of structured multidisciplinary care on outcomes remains underexplored. METHODS AND RESULTS: ACT-SHOCK is a service evaluation at a UK tertiary cardiac centre. Between May 2023 and May 2024, 82 patients with AMI-related CS requiring emergent percutaneous coronary intervention (PCI) were identified using protocolised physiological criteria and managed by an Advanced Cardiogenic-Shock Team (ACT). The ACT comprised interventional cardiologists, intensivists, anaesthetists, critical care staff and cardiac physiologists, coordinating PCI and ongoing care. Outcomes were compared with 83 historical controls from the year preceding ACT roll-out, who received standard care without ACT activation. Primary endpoints were 30-day and 1-year all-cause mortality; secondary outcomes included predictors of 30-day mortality.Within the ACT cohort, elevated lactate, critical care admission, invasive ventilation, out-of-hospital cardiac arrest and Society for Cardiovascular Angiography and Interventions (SCAI) Shock Stage E at first medical contact predicted 1-year mortality. Adjusted analyses showed ACT management was associated with lower 1-year mortality compared with standard care (HR 0.53, 95% CI 0.30 to 0.92; p=0.026). Although 30-day mortality was lower in the ACT group, this did not reach statistical significance (HR 0.71, 95% CI 0.39 to 1.29; p=0.26). Escalation from coronary care to critical care during the recovery phase occurred more promptly in the ACT group (9.7% vs 2.4%, p=0.09). At 24 hours, a smaller proportion of ACT patients remained in SCAI stages D/E compared with standard care (42% vs 48%; p=0.003). CONCLUSIONS: Implementation of physiological criteria to identify CS and activation of a multidisciplinary ACT in a UK tertiary centre was associated with earlier detection and improved 1-year survival in AMI-related CS. These pilot data support further study across multiple UK centres to inform national policy and standardise care pathways.