ABC | Volume 113, Nº4, October 2019

Updated Updated Cardiovascular Prevention Guideline of the Brazilian Society Of Cardiology – 2019 Arq Bras Cardiol. 2019; 113(4):787-891 More than 200 million people worldwide are estimated to have diverse stages of PAD, ranging from the asymptomatic phase of the disease to intermittent claudication (IC) and the more severe late stages of the disease. 485 Prevalence increases with aging, rising by more than 10% in patients aged 60 to 70 years; and over 20% in patients over 80 years of age. Although the prevalence of symptomatic and more severe forms of PAD is higher in men, a recent study of 3.6 million individuals in the US has shown that women may be worsening the odds of developing the disease compared to men (odds ratio [OR] of 1.62, 95% confidence interval between 1.60-1.64). Inversely, women were less prone to carotid stenosis or abdominal aortic aneurysm (AAA) than men. 485,486 Publications of previous decades already evidenced that the simultaneous presence of PAD and CVD or cerebrovascular is frequent, especially at older ages. Likewise, the anatomopathological characteristics and clinical manifestations of CVD in patients with PAD are usually more severe, with a higher occurrence of multivessel coronary branch injury and a higher prevalence of left coronary trunk injury. 487,488 10.5.2. Interrelationship between the Various Cardiovascular Risk Factors and Lower Extremity Peripheral Artery Disease In most studies, the proportion of symptomatic patients ranges from 20 to 33%, among all patients with PAD. In the Swedish population aged 60-90 years, the prevalence of lower extremity PAD was 18% and intermittent claudication 7%. 489 In Brazil, a multicenter cross-sectional study evaluated 1,170 individuals in 72 urban centers. The prevalence of intermittent claudication was 9% among those with ABI below the cutoff point of 0.9. In this analysis, women with coronary artery disease were 4.9 times more at risk for lower extremity PAD. 490 Arterial Hypertension: Hypertension increases the chance of lower extremity PAD by 32% up to 2.2 times in various epidemiological studies. Although the risk of hypertension causing lower extremity PAD has been modest in some studies, the high prevalence of this risk factor among the elderly reinforces the epidemiological burden of lower limb arteriopathy. 489 A comprehensive study of more than 4.2 million individuals in primary health care in the UK, investigated the association between hypertension and the risk of lower extremity PAD. In this study, with each 20 mmHg increase in systolic blood pressure in hypertensive men aged 40-79 years, the risk of lower extremity PAD increased by 63%. Lower extremity PAD was associated with an increased risk of ischemic heart disease, CKD, HF, aortic aneurysm and atrial fibrillation; however, it was not associated with hemorrhagic stroke. 491 The Harmonica Project, a Finnish community-based report, showed that the prevalence of asymptomatic (without claudication) lower extremity PAD, by means of ABI, was 7.3% in 532 hypertensive subjects, compared with 2.3% in 440 normotensive individuals. By adjusting multiple variables, hypertension continued to be an independent risk factor associated with lower extremity PAD, more than tripling the occurrence of lower limb arterial involvement (OR: 3.20). Hypertensive patients with borderline and altered ABI represented one third of all participants with hypertension in the average age range of 60 ± 7 years. 492 Smoking: This is a particularly prominent risk factor in atherosclerotic disease of the lower extremities. The prospective Health Professionals Follow-up Study (HPFS) investigated 44,985 men with lower extremity PAD aged 40 to 75 years with a history of limb amputation, need for revascularization, arterial angiographic injury > 50% occlusion, and ABI below 0, 90. The authors followed the attributable risk of four of the most traditional risk factors, diabetes, hypertension, hypercholesterolemia, and smoking, by a median follow-up of 24.2 years. Active smoking significantly increased the adjusted risk of lower extremity PAD by 12.89-fold (95% confidence interval between 8.59 and 19.34), compared with individuals who had never smoked. Also, in participants who stopped smoking for more than 20 years, the risk of lower extremity PAD remained 39% higher than in those who had never smoked. 493 The Guangzhou Biobank Cohort Study (GBCS) evaluated the association between second-hand smoke exposure and lower extremity PAD in non-smokers. By adjusting for confounding variables, exposure to residential passive smoke for 25 hours / week or more was significantly associated lower extremity PAD (OR = 7.86; p = 0.003). 494 Diabetes: The presence of diabetes increases the risk of lower extremity PAD by 1.9 to 4 times compared to non- diabetics. 489 In our country, the risk of diabetic men developing lower extremity PAD was 6.6 times higher than that of non- diabetics. 490 A case-control trial in patients with diabetic foot investigated ulcers that progressed to amputation. After adjusting several variables, at least three widely known risk factors were predictors of amputation risk: i. HbA1c level > 8% (p = 0.002); ii. hypertriglyceridemia (p = 0.004); and iii. hypertension (p = 0.028).495 The risk of lower extremity PAD tends to increase with the duration and evolution of both metabolic factors, diabetes (p < 0.001) and hypercholesterolemia (p = 0.05) over time. 493 Dyslipidemia: Hypercholesterolaemia increases the risk of developing lower extremity PAD by 90% (p = 0.05). 493 FH is an autosomal dominant condition associated with mutations in the LDL receptor-encoding gene or ApoB and PCSK-C coding genes. 9 In a Brazilian cross-sectional study, 202 patients with heterozygous FH were compared to 524 normolipidemic controls. The prevalence of lower extremity PAD in the FH group went from 17.3 to 2.3% in the group with appropriate lipid profile (p < 0.001). 496 Classic risk factors continue to play a relevant role when lower extremity PAD progresses to more severe forms of vascular impairment, such as critical lower limb ischemia (CLI) or acute limb ischemia. Such presentations of lower extremity PAD have a poor prognosis in terms of disability and death. The UK-based prospective population-based Oxford Vascular Study (OXVASC) analyzed the incidence of severe peripheral ischemic outcomes in 92,728 patients. Compared with the control population, the occurrence of unstable events was associated with risk factors: i. hypertension: adjusted risk of 2.75 times; ii. smoking: adjusted risk of 2.14; 845