Peripheral arterial disease in patients with stages IV and V chronic renal failure.

BACKGROUND

Cardiovascular disorders are frequently found among chronic renal failure (CRF) patients due to their higher susceptibility to develop atherosclerosis. However, peripheral arterial disease (PAD), that is associated with a high mortality rate, is not usually assessed in these patients. The aims of this study are to find out the prevalence of PAD affecting lower limbs in a population of CRF patients in stages IV/V, and to assess how much PAD determines the 5-year patient survival.

METHODS

The study population (44 males and 29 females) was aged 58 +/- 15 years. They suffered from advanced CRF (18.6 +/- 6.1 ml/min creatinine clearance), but they were not on dialysis. These patients were sequentially referred initially to the predialysis unit over a period of 14 months. The vascular lesions were assessed by carotid and transcranial ultrasound, as well as by ankle-brachial index test (ABI). Routine 24 h blood and urine laboratory tests were performed for each patient. Cardiovascular morbidity and cardiovascular disease risk factors were evaluated through personal interview.

RESULTS

Fourteen patients had an ABI index of less than 0.91 (PAD indicative), 11 of them also suffered from intermittent claudication. PAD affected significantly more males (P = 0.001) and diabetics (P = 0.001). Also, PAD prevalence was significantly higher in patients with a previous clinical record of coronary heart disease (P = 0.001), increased clinical record of cerebrovascular disease (P = 0.005), a thickness of the left ventricular posterior wall (P = 0.03) and lower cardiac ejection fraction (P = 0.02). PAD patients had a significantly different protein intake (P = 0.003), calcium-phosphorus product (P = 0.001), risk of coronary heart disease based on the Framingham score (P = 0.001) and 5-year survival rate (P = 0.004). There were no significant differences for PAD patients in terms of body mass index, creatinine clearance, lipid profile, Ca and P. Multivariate risk factor analysis revealed that a previous clinical record of coronary heart disease and diabetes increased the risk of developing PAD, as defined by ABI < 0.91. After 5 years, 21 patients (29%) had died: 64% of patients that suffered PAD (9/14) and 20% of the non-PAD population (12/59). The Cox proportional hazards model demonstrated that older age and a lower ABI increased the risk of death.

CONCLUSIONS

The present study, conducted on CRF patients in stages IV and V not undergoing dialysis, showed; (a) that a high percentage of these patients developed PAD (19%) or other vascular pathologies; (b) that there was an associated high mortality rate (29%) after 5 years; (c) that the 5-year mortality rate was significantly higher (P = 0.004) in PAD patients (64 vs 20%).