THE ROLE OF THE MACRUZ INDEX IN STROKE PATIENTS: PREDICTIVE VALUE AND ATRIAL REMODELING

Introduction: Atrial fibrillation (AF) is the most common arrhythmia involved in the etiology of stroke. Even stroke patients without AF, who are in sinus rhythm, may exhibit atrial electrical abnormalities. The Macruz index, which is the focus of our study, is defined on electrocardiography (ECG) as the ratio of the P-wave duration to the PQ (PR) segment duration and is normally considered to be within the range of approximately 0.9–1.1. A value above 1.1 is associated with atrial conduction disturbance or left atrial enlargement, whereas a value below 0.9 suggests prolongation of the PQ segment or shortening of the P-wave. The Macruz index is a surface ECG marker that reflects atrial conduction delay and enlargement. Clinically, it is an important parameter used to predict the risk of atrial fibrillation development, to assess atrial enlargement, to determine the prognosis of cardiovascular diseases such as hypertension and stroke, and to detect atrial conduction disorders. This study aimed to investigate the clinical significance of the Macruz index in stroke patients with normal sinus rhythm. Methods: Between April 15, 2025, and September 15, 2025, 89 stroke patients who were hospitalized in the neurology department of Gazi Yaşargil Training and Research Hospital, received cardiology consultations, and showed no AF on 24-hour Holter monitoring (sinus rhythm) were included in the study. For the control group, 106 patients who presented to the cardiology outpatient clinic during the same period with complaints of palpitations but had sinus rhythm on their admission ECGs were included. The ECGs of these patients were reviewed, and their Macruz indexes were calculated. Clinical, laboratory, and electrocardiographic data were compared. Regression analyses were performed to determine independent predictors. Results: Stroke patients had a significantly higher Macruz index compared with the control group (1.9 ± 0.8 vs. 1.2 ± 0.5, p < 0.001). In multivariable analysis, age (β = 0.010, p =0.040) and neutrophil-to-lymphocyte ratio (NLR) (β = 0.110, p = 0.002) were independent predictors. HDL cholesterol showed a marginal inverse association (p = 0.052). Conclusions: An elevated Macruz index may reflect atrial remodeling in stroke patients even in the absence of AF. This index may serve as an early indicator of atrial vulnerability and arrhythmogenic potential, suggesting the need for extended rhythm monitoring in this population.