Neck-to-Waist Ratio Identifies Chronic Hypertensive Phenotype and Occlusive Myocardial Infarction in Patients Presenting With Acute Coronary Syndrome

Patients presenting to the ED with chest pain or anginal equivalents who were diagnosed with ACS after evaluation with physical examination, cardiac biomarkers, and imaging studies, and who were subsequently hospitalized for coronary imaging, were included in the study. Patients excluded from the study are presented in the study flowchart (Figure 1).

Vital parameters, including initial admission BP, pulse rate, oxygen saturation (SpO₂), and heart rate, as well as electrocardiographic findings, were recorded. Laboratory parameters obtained at initial admission, including complete blood count, biochemical parameters, blood gas analysis, and cardiac troponin levels, were recorded. Additional laboratory findings obtained after hospitalization, including uric acid, lipid profile, and proBNP levels, were also documented. Echocardiographic measurements performed prior to the procedure were recorded.

Anthropometric measurements were obtained immediately before the procedure or within the first 24 hours after the procedure. NC, WC, HC, and TC measurements were performed and waist-to-hip ratio (WHR), waist-to-thigh ratio (WTR), neck-to-waist ratio (NWR) were calculated accordingly. All anthropometric measurements were obtained in accordance with the standardized procedures outlined in the NHANES Anthropometry Procedures Manual [12]. Body weight was measured in kilograms using a digital weight scale, and height was measured in centimeters using a height scale. Anthropometric measurements were obtained in centimeters using a measurement tape and recorded accordingly.

Findings obtained after coronary angiography, including the affected vessel, number of involved vessels, degree of involvement, and procedures performed (PTCA, stent implantation, thrombus aspiration, CABG, no intervention), were documented.

Length of hospital stay (ward and intensive care unit), recurrent ED admissions, and 30-day mortality were also recorded. In this study, occlusive myocardial infarction (OMI) was defined as the presence of an acute culprit lesion causing complete or near-complete limitation of coronary blood flow (TIMI flow grade 0-2) requiring emergent reperfusion therapy, and patients were classified according to coronary angiographic findings.

Patients were divided into two groups according to BP measurements obtained at ED admission: elevated admission BP (systolic BP ≥135 mmHg and/or diastolicBP ≥85 mmHg) and normal admission BP groups ( systolic BP <135 or diastolic BP<85 and MAP >65 mmHg). Differences between these two groups were evaluated in terms of anthropometric measurements, laboratory and echocardiographic parameters, clinical outcomes, and the requirement for coronary intervention. Additionally, the same analyses were repeated after dividing the patients into two groups according to the presence or absence of previously known hypertension as comorbidity. Furthermore, patients with known hypertension were further subgrouped into elevated admission BP (systolic BP ≥135 mmHg and/or diastolic BP ≥85 mmHg) and normal admission BP groups, and the same analyses were performed again within these subgroups.

Inclusion criteria

• Patients presenting to the emergency department with chest pain or anginal equivalents, diagnosed with ACS, admitted to CICU for coronary angiography
• aged over 18 years

Exclusion criteria

• Patients with anatomical abnormalities in the regions where anthropometric measurements were to be performed (n=11)
• Patients with endocrinological disorders causing anatomical abnormalities of the neck, waist, or hip circumference (n=3)
• Patients with neck tumors (n=1)
• ACS patients who did not undergo coronary angiography(n=6)
• Etiologies causing secondary troponin elevation (e.g., pulmonary embolism, aortic dissection, hypoxia-related pathologies, sepsis, and anemia) (n=51)
• Mean arterial pressure < 65 mmHg (n=9)
• Patients unable to stand upright (n=18)
• Patients with ascites (n=1)