Clinical characteristics and intravascular ultrasound findings of culprit lesions in elderly patients with acute coronary syndrome

Acute coronary syndrome (ACS) is one of the main causes of cardiovascular death. According to rapid aging of society, the peak age of ACS onset has grown older globally. Despite growing recognition of the necessity to build the ACS prevention strategy in the elderly, patients background and culprit lesion morphology of these elderly ACS patients have not been well studied. We sought to assess the clinical characteristics and intravascular ultrasound (IVUS) findings of the culprit lesions in elderly ACS patients. One-hundred and fifty-eight consecutive ACS patients whose culprit lesions imaged by pre-intervention IVUS were divided into two groups based on the age of onset: elderly [E] group (≥75 years, n = 65) and non-elderly [NE] group (<75 years, n = 93). As compared with NE group, hemoglobin (12.7 ± 2.0 g/dL vs. 13.7 ± 1.6 g/dL, p = 0.001), estimated glomerular filtration rate (62.5 ± 22.5 mL/min/1.73 m² vs. 75.5 ± 20.5 mL/min/1.73 m², p = 0.0001), and body mass index (22.9 ± 3.4 kg/m² vs. 24.5 ± 3.4 kg/m², p = 0.003) were significantly lower, and comorbid malignancy was more common (20.0 vs 6.5 %, p = 0.01) in E group. Although whole culprit segment was not positively remodeled (mean vessel area was 15.2 ± 5.6 mm³/mm vs. 16.2 ± 5.1 mm³/mm, p = 0.16) in E group, at maximum external elastic membrane site of the culprit lesion, lumen area was smaller (5.5 ± 3.2 mm² vs. 6.7 ± 3.5 mm², p = 0.04), and plaque burden tended to be more abundant (70 ± 13 vs. 66 ± 13 %, p = 0.08). Interestingly, echo attenuation arc of culprit attenuated plaque was significantly greater in E group than in NE group (157 ± 83° vs. 118 ± 60°, p = 0.01). In conclusion, extracardiac comorbidity was more common in elderly ACS patients, and their culprit coronary lesions were still rupture prone, and “vulnerable.”