Abstract / Summary
Microvascular injury (MVI), commonly assessed on cardiac magnetic resonance (CMR) as microvascular obstruction (MVO), is frequently observed in patients with ST-elevation myocardial infarction (STEMI) despite timely primary percutaneous coronary intervention (PPCI), and is key to adverse left ventricular (LV) remodelling and poor outcomes. Established invasive indices, such as the index of microvascular resistance (IMR), are obtained after reperfusion and therefore do not capture microvascular compromise present during coronary occlusion. Coronary wedge pressure (CWP), obtained during balloon occlusion, is a simple invasive marker of microvascular function, but its clinical value remains uncertain. To determine whether pre-reperfusion CWP, coronary flow pressure index (CFPI) and related pressure-derived indices are associated with (i) the presence of CMR-defined MVO and (ii) MVO extent in anterior STEMI patients treated with selective intracoronary hypothermia (SIH). Secondary objectives were associations with intramyocardial haemorrhage (IMH) and myocardial salvage index (MSI). In this EUROICE substudy, distal coronary pressure was recorded during culprit LAD occlusion in patients randomised to selective intracoronary hypothermia. Systolic, diastolic and mean CWP, CFPI and outflow time (τ) were derived. CMR at 2-7 days quantified MVO, intramyocardial haemorrhage (IMH) and myocardial salvage index (MSI). Associations were analysed using Spearman correlation, parsimonious multivariable logistic regression, and receiver operating characteristic analysis. Of 94 patients randomised to selective intracoronary hypothermia, 82 had paired pre-reperfusion physiology and CMR data available, of whom 65 had interpretable coronary pressure traces. Mean wedge pressure was 21.4 ± 11.0 mmHg, CFPI 0.24 ± 0.11, and τ 5.2 ± 2.6 s. MVO was present in 64% of patients (mean extent 2.7 ± 4.6% of LV mass). Lower CWP and CFPI were associated with MVO presence and extent (CFPI ρ = -0.33, p = 0.008), whereas τ was not. Lower CWP and CFPI were inversely related to IMH, but not to MSI. In complete-case multivariable models, lower CFPI remained associated with MVO presence (adjusted OR 0.91 per 0.01 increase, 95% CI 0.86-0.97, p = 0.002), as did lower mean CWP (adjusted OR 0.91 per 1 mmHg increase, 95% CI 0.85-0.97, p = 0.003). CFPI showed moderate discrimination for MVO, with an AUC of 0.74 (95% CI 0.61-0.87), while mean CWP showed similar discrimination, with an AUC of 0.74 (95% CI 0.61-0.86). Lower CWP before reperfusion and CFPI during balloon occlusion were associated with greater MVO and IMH on early CMR in anterior STEMI. These indices support the feasibility of pre-reperfusion physiological phenotyping to aid on-table microvascular risk stratification.
Primary Source
International journal of cardiology
Ask Prognia AI
Have questions about this randomised trial?
Prognia AI can search this source alongside 35M+ PubMed papers and current ESC, AHA, NICE, and ADA guidelines to give you a fully cited clinical answer.
Related Clinical Guidelines
Related Blog Posts
ESC 2023 Heart Failure Guidelines: What Every Cardiologist Needs to Know
The 2023 focused update to the ESC Heart Failure Guidelines introduced key changes to SGLT2 inhibitor recommendations, HFmrEF management, and device therapy thresholds. Here is a practical summary.
CHADS₂-VASc in Practice: When to Start Anticoagulation in AF
A practical walkthrough of the CHADS₂-VASc scoring system, its ESC guideline thresholds, and how to use it alongside HAS-BLED to counsel patients with atrial fibrillation.