Computed tomography characteristics of coronary artery atherosclerosis in subjects with lower extremity peripheral artery disease and no cardiac symptoms.

INTRODUCTION:  Computed tomography coronary angiography (CTCA) enables noninvasive evaluation of coronary artery atherosclerosis. However, its value to assess coronary artery disease (CAD) in subjects with lower­extremity peripheral artery disease (PAD) and no cardiac symptoms is unknown. Moreover, the relationship between coronary artery plaque characteristics and severity of peripheral atherosclerosis in this group of patients was not sufficiently elucidated. OBJECTIVES:  The aim of the study was to determine the value of CTCA to assess coronary artery atherosclerosis and to evaluate the relationship between coronary artery plaque characteristics and severity of peripheral atherosclerosis in subjects with lower­extremity PAD and no cardiac symptoms. PATIENTS AND METHODS:  Sixty­five individuals (45 men, 20 women, mean age, 62.5 ±7.6 years) with lower­extremity PAD and no cardiac symptoms underwent CTCA. RESULTS:  CTCA revealed CAD in 56 subjects. Twenty­two had obstructive CAD. The mean ankle-brachial index (ABI) was 0.64 ±0.16. Twenty­six individuals demonstrated abnormal carotid artery intima-media thickness (IMT). ABI lower than median, if compared with ABI equal of higher than median, was associated with a higher proportion of obstructive multivessel to single vessel CAD (8:4 vs. 1:9; P = 0.01) and higher number of coronary artery segments with mixed plaques (2.3 ±2.2 vs. 1.2 ±1.3; P = 0.02). Comparing patients with abnormal and normal IMT, the former demonstrated higher proportion of obstructive multivessel to single-vessel CAD (7:3 vs. 2:10; P = 0.01) and higher number of coronary artery segments with noncalcified (1.9 ±3.2 vs. 0.6 ±1.4; P = 0.04) and mixed plaques (2.3 ±2.1 vs. 1.3 ±1.7; P = 0.049). CONCLUSIONS:  CTCA may be effective to detect CAD in subjects with lower­extremity PAD and no cardiac symptoms. The low ABI and abnormal IMT are associated with more extensive CAD and higher burden of high­risk coronary artery plaques.

Altered fibrin clot properties in patients with premature peripheral artery disease.

INTRODUCTION: It has been shown that formation of denser and poorly lysable fibrin clots is observed in elderly patients with peripheral artery disease (PAD). OBJECTIVES: The aim of the study was to test the hypothesis that premature PAD is associated with more prothrombotic fibrin clot phenotype. PATIENTS AND METHODS: Ex­vivo plasma fibrin clot permeability, turbidity, and susceptibility to lysis were evaluated in 31 premature PAD patients (median ankle brachial index [ABI], 0.75; interquartile range, 0.5-0.8) aged 55 or less and 32 PAD patients (ABI, 0.66; 0.56-0.76) aged over 55 years. Subjects without PAD matched for age and sex (n = 40) served as controls. RESULTS: Premature PAD patients were characterized by 32% lower clot permeability (Ks) (P <0.001), 7% longer clot lysis time (t50%) (P = 0.004), and 31% higher maximum D-dimer levels released from fibrin clots (D-Dmax) (P <0.001) compared with controls. These differences remained significant after adjustment for risk factors and medications. None of the fibrin clot parameters differed between premature and older PAD patients. There were correlations between fibrin clot parameters and CRP in premature PAD patients and with ABI in older PAD patients. In a multiple regression model, premature PAD and ABI were independent predictors of Ks, and premature PAD and plasma fibrinogen of the maximum absorbance of a fibrin gel. CONCLUSIONS: Plasma fibrin clots show similarly abnormal prothrombotic phenotype in premature and older PAD patients. However, different factors influence fibrin clot parameters in these patient groups. Premature PAD was an independent predictor of clot permeability and maximum absorbance of a fibrin gel.