Correlation between platelet-to-white blood cell ratio and left ventricular myocardial strain in patients with ST-segment elevation myocardial infarction undergoing percutaneous coronary intervention: a cardiac magnetic resonance feature-tracking study

Background: Left ventricular (LV) myocardial strain derived from cardiac magnetic resonance (CMR) feature tracking enables sensitive detection of subclinical myocardial dysfunction after ST-segment elevation myocardial infarction (STEMI). However, factors associated with early post-infarction LV myocardial function following percutaneous coronary intervention (PCI) remain incompletely understood, particularly in the context of inflammation-related myocardial injury. The platelet-to-white blood cell ratio (PWR) which combines two routinely measured blood cell counts and may reflect the dynamic interplay between platelet recovery and inflammatory dynamics, has emerged as a potential biomarker of systemic inflammatory status. This study investigated the association between PWR and LV myocardial strain in patients with STEMI after PCI. Methods: This retrospective single-center study included 222 patients with STEMI who underwent CMR imaging within 1 week after PCI. Demographic information, laboratory test results, and CMR parameters were collected. Multivariable logistic regression, restricted cubic spline (RCS), subgroup, sensitivity and nonlinear analyses were performed to investigate the association between post-PCI PWR and CMR-derived LV myocardial strain. Results: Patients in the highest PWR quartile had significantly higher LV ejection fraction (LVEF) (53.4% vs. 45.0%, P<0.001) and a smaller median infarct size (IS) (11.9% vs. 18.8%, P=0.006) than those in the lowest quartile (Q1). In the fully adjusted logistic model, higher PWR was independently associated with lower odds of impaired global longitudinal strain (GLS) [odds ratio (OR) 0.13, 95% confidence interval (CI): 0.05–0.30, P<0.001] and impaired global circumferential strain (GCS) (OR 0.18; 95% CI: 0.06–0.49; P=0.001), and with higher odds of preserved global radial strain (GRS) (OR 5.57; 95% CI: 2.06–15.06; P=0.001). RCS analysis showed a linear association between PWR and the odds of LV myocardial strain impairment. Subgroup and sensitivity analyses yielded similar associations. Conclusions: A higher post-PCI PWR was independently associated with more favorable LV myocardial strain after PCI in patients with STEMI. As a routinely available ratio, PWR may complement the early description of myocardial strain impairment.