Angiography-versus wire-based microvascular resistance index to detect coronary microvascular obstruction associated with ST-segment elevation myocardial infarction.

BACKGROUND: Microvascular obstruction (MVO) measured by cardiac magnetic resonance (CMR) after ST-segment elevation myocardial infarction (STEMI) has important prognostic implications. While invasive index of microvascular resistance (IMR) have been shown to predict the occurrence and extent of MVO, the role of the angiography-based microvascular resistance (Angio-IMR) for this purpose remains unknown. The present study aims to perform a head-to-head comparison of wire-based and angiography-derived microcirculatory resistance (IMR and Angio-IMR, respectively) for the detection of MVO. METHODS: Patients with a first STEMI and multivessel disease underwent CMR for detection of MVO, and angio-IMR and IMR measurements during PPCI and at 30 day follow up, both in STEMI culprit and non-culprit vessels. RESULTS: 58 patients were included (mean age 60.7 ± 9.9 years, 82% male). At the time of PPCI, angio-IMR and IMR exhibited significant correlation (r = 0.70, P < 0.001), and agreement (coefficient of agreement 0.58). Both indices showed good predictive value of MVO [Angio IMR: AUC 0.79 (95% CI: 0.667-0.928); IMR: AUC 0.70 (95% CI: 0.539-0.853); p = 0.15]. Angio-IMR 40 U and IMR 34 U were identified as best cut-offs for prediction of MVO. In non-culprit vessels, angio-IMR and IMR also correlated well (rho = 0.59, p < 0.001), with overall lower mean values compared to culprit vessels (Angio-IMR: 36 vs. 23; IMR: 39 vs. 22, p < 0.001 for both comparisons). CONCLUSION: Angio-IMR constitutes a valid alternative to wire-based IMR in predicting MVO in STEMI. Angio-IMR and IMR show a good correlation in the acute and subacute STEMI phases, both in culprit and non-culprit vessels.

Prognostic Value of Microvascular Resistance Reserve After Percutaneous Coronary Intervention in Patients With Myocardial Infarction.

BACKGROUND: The microvascular resistance reserve (MRR) has recently been introduced as a novel index to assess the vasodilatory capacity of the microcirculation, independent of epicardial disease. The prognostic value of MRR in ST-segment elevation myocardial infarction (STEMI) is unknown. OBJECTIVES: The aim of this analysis was to investigate the prognostic value of MRR in patients with STEMI and to compare MRR with cardiovascular magnetic resonance imaging parameters. METHODS: From a pooled analysis of individual patient data from 6 cohorts that measured the index of microcirculatory resistance (IMR) directly after primary percutaneous coronary intervention in patients with STEMI (n = 1,265), a subgroup analysis was performed in patients in whom both MRR and IMR were available. The primary endpoint was the composite of all-cause mortality or hospitalization for heart failure. RESULTS: Both MRR and IMR could be calculated in 446 patients. The optimal cutoff of MRR to predict the primary endpoint in this STEMI population was 1.25. During a median follow-up of 3.1 years (Q1-Q3: 1.5-6.1 years), the composite of all-cause mortality or hospitalization for heart failure occurred in 27.3% and 5.9% of patients (HR: 4.16; 95% CI: 2.31-7.50; P < 0.001) in the low MRR (≤1.25) and high MRR (>1.25) groups, respectively. Both IMR and MRR were independent predictors of the composite of all-cause mortality or hospitalization for heart failure. CONCLUSIONS: MRR measured directly after primary percutaneous coronary intervention was an independent predictor of the composite of all-cause mortality or hospitalization for heart failure during long-term follow-up.

Ultrasound-guided versus fluoroscopy-guided large-bore femoral access in PCI of complex coronary lesions: the international, multicentre, randomised ULTRACOLOR Trial.

BACKGROUND: Transfemoral access is often used when large-bore guide catheters are required for percutaneous coronary intervention (PCI) of complex coronary lesions, especially when large-bore transradial access is contraindicated. Whether the risk of access site complications for these procedures may be reduced by ultrasound-guided puncture is unclear. AIMS: We aimed to show the superiority of ultrasound-guided femoral puncture compared to fluoroscopy-guided access in large-bore complex PCI with regard to access site-related Bleeding Academic Research Consortium 2, 3 or 5 bleeding and/or vascular complications requiring intervention during hospitalisation. METHODS: The ULTRACOLOR Trial is an international, multicentre, randomised controlled trial investigating whether ultrasound-guided large-bore femoral access reduces clinically relevant access site complications compared to fluoroscopy-guided large-bore femoral access in PCI of complex coronary lesions. RESULTS: A total of 544 patients undergoing complex PCI mandating large-bore (≥7 Fr) transfemoral access were randomised at 10 European centres (median age 71; 76% male). Of these patients, 68% required PCI of a chronic total occlusion. The primary endpoint was met in 18.9% of PCI with fluoroscopy-guided access and 15.7% of PCI with ultrasound-guided access (p=0.32). First-pass puncture success was 92% for ultrasound-guided access versus 85% for fluoroscopy-guided access (p=0.02). The median time in the catheterisation laboratory was 102 minutes versus 105 minutes (p=0.43), and the major adverse cardiovascular event rate at 1 month was 4.1% for fluoroscopy-guided access and 2.6% for ultrasound-guided access (p=0.32). CONCLUSIONS: As compared to fluoroscopy-guided access, the routine use of ultrasound-guided access for large-bore transfemoral complex PCI did not significantly reduce clinically relevant bleeding or vascular access site complications. A significantly higher first-pass puncture success rate was demonstrated for ultrasound-guided access. CLINICALTRIALS: gov identifier: NCT04837404.