Peripheral arterial disease: epidemiology and drug therapy

Effect of supervised exercise training on cardiovascular function in patients with intermittent claudication: a systematic review and meta-analysis of randomized controlled trials

This study aimed to determine the effect of supervised exercise training (SET) on cardiovascular function in patients with intermittent claudication (IC). A systematic search in MEDLINE, Embase, and Cochrane Central Register of Controlled Trials databases was conducted. Primary outcomes were systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), rate pressure product (RPP), cardiac output (CO), peak oxygen consumption (VO2peak), and heart rate variability (HRV). Secondary outcomes were maximum walking distance (MWD) and pain-free walking distance (PFWD). Outcomes were reported as weighted mean difference (WMD) between the SET group and the control group and synthesized by using the random-effects model. Seventeen RCTs with a total of 936 patients were included in this review. SET resulted in significant improvements of SBP (WMD =  - 7.40, 95% CI - 10.69 ~  - 4.11, p < 0.001, I2 = 15.2%), DBP (WMD =  - 1.92, 95% CI - 3.82 ~  - 0.02, p = 0.048, I2 = 0.0%), HR (WMD =  - 3.38, 95% CI - 6.30 ~  - 0.46, p = 0.023, I2 = 0.0%), RPP (WMD =  - 1072.82, 95% CI - 1977.05 ~  - 168.59, p = 0.020, I2 = 42.7%), and VO2peak with plantar flexion ergometer exercise (WMD = 5.57, 95% CI 1.66 ~ 9.49, p = 0.005, I2 = 62.4%), whereas CO and HRV remained statistically unaltered. SET also improved MWD (WMD = 139.04, 95% CI 48.64 ~ 229.44, p = 0.003, I2 = 79.3%) and PFWD (WMD = 40.02, 95% CI 23.85 ~ 56.18, p < 0.001, I2 = 0.0%). In conclusion, SET is effective in improving cardiovascular function in patients with IC, which was confirmed on outcomes of cardiovascular function associated with exercise ability. The findings hold out that the standard therapy of SET can improve not only walking distance but also cardiovascular function in patients with IC.

Exercise training for intermittent claudication: a narrative review and summary of guidelines for practitioners

Peripheral artery disease (PAD) is caused by atherosclerotic narrowing of the arteries supplying the lower limbs often resulting in intermittent claudication, evident as pain or cramping while walking. Supervised exercise training elicits clinically meaningful benefits in walking ability and quality of life. Walking is the modality of exercise with the strongest evidence and is recommended in several national and international guidelines. Alternate forms of exercise such as upper- or lower-body cycling may be used, if required by certain patients, although there is less evidence for these types of programmes. The evidence for progressive resistance training is growing and patients can also engage in strength-based training alongside a walking programme. For those unable to attend a supervised class (strongest evidence), home-based or 'self-facilitated' exercise programmes are known to improve walking distance when compared to simple advice. All exercise programmes, independent of the mode of delivery, should be progressive and individually prescribed where possible, considering disease severity, comorbidities and initial exercise capacity. All patients should aim to accumulate at least 30 min of aerobic activity, at least three times a week, for at least 3 months, ideally in the form of walking exercise to near-maximal claudication pain.

Knowledge of peripheral arterial disease: Results of an intervention to measure and improve PAD knowledge in Toronto

Background

Prevalence of peripheral arterial disease (PAD) has dramatically increased in both developing, as well as developed countries. However, significant knowledge and practice gaps persist. In Canada, efforts to improve this knowledge level are lacking. In this study, we examine PAD knowledge in Toronto, and evaluate a pilot intervention to address the knowledge gaps.

Objectives

Measure PAD awareness in Toronto, and evaluate an intervention to improve PAD knowledge among the public.

Methods

In the context of a community-based awareness campaign, an interview-based survey was used to assess the PAD awareness among general public. A sample of participants was split into two arms: control (survey only) and intervention (survey and education pamphlet), the choice between assigning the site as case or control was random. A follow-up telephone and email-based survey was conducted after 6 weeks to assess the attained knowledge level of PAD.

Results

Two hundred thirty-seven participants completed the baseline survey. One hundred eighty-eight participants (78.7%) had never heard of PAD. The remaining “PAD-aware” cohort had low overall knowledge of the disease characteristics. Participants from each arm completed the follow-up survey. The level of education, age, and gender were not predictors of knowledge scores; however, age was a predictor of PAD awareness, while gender and level of education were not. Participants in the intervention group showed significant knowledge scores improvement in five PAD domains, while those from control group showed significant improvement in their preventative measures, treatment modalities, and total scores. The impact of the study intervention on average scores was borderline not significant ( p = 0.05).

Conclusion

PAD knowledge gap in the Canadian public is larger than what was previously reported. Educational campaigns are necessary to address this gap and improve the outcome of PAD patients through patients' activation. Our results are encouraging and warrant a next intervention to explore an educational program impact on PAD knowledge.

[Multiple obliterative vascular disease. Challenge in diagnosis and in treatment]

Currently, peripheral arterial disease is an underdiagnosed disorder. Several modifiable and non-modifiable risk factors have role in its development and progression. As system disorder it might be a part and an important predictor of fatal cardio- and cerebrovascular events.

CASE REPORT

The authors describe the case of a 73-year-old male with multilocational vascular disorder, with simultaneously occurring carotid disease, critical limb ischaemia with aorto-bifemoral bypass, multiple infarction with mechanical complication, inoperable coronary disease and with implantable cardioverter defibrillator for ventricular arrhythmia.

CONCLUSION

Peripheral arterial disease affects the whole vascular system and can progress into serious cardiac and cerebral manifestations causing the patient's death inspite of comprehensive treatment.

Bilateral claudication results in alterations in the gait biomechanics at the hip and ankle joints

Claudication is the most common symptomatic manifestation of peripheral arterial disease (PAD), producing significant ambulatory compromise. The purpose of this study was to use advanced biomechanical gait analysis to determine the gait alterations occurring in claudicating patients both before and after onset of claudication pain in their legs. Hip, knee, and ankle joint moments were measured in claudicating patients (age: 64.46+/-8.47 years; body mass: 80.70+/-12.64kg; body height: 1.72+/-0.08m) and were compared to gender-age-body mass-height-matched healthy controls (age 66.27+/-9.22 years; body mass: 77.89+/-10.65kg; body height: 1.74+/-0.08m). The claudicating patients were evaluated both before (pain-free (PF) condition) and after (pain condition) onset of claudication pain in their legs. Thirteen symptomatic PAD patients (26 claudicating limbs) with bilateral intermittent claudication (IC) and 11 healthy controls (22 control limbs) were tested during level walking at their self-selected speed. Compared to controls, PAD hip and ankle joints demonstrated significant angular kinematics and net internal moment changes. Alterations were present both in PF and pain conditions with several of them becoming worse in the pain condition. Both PF and pain conditions resulted in significantly reduced peak hip extensor moment (5.62+/-1.40 and 5.63+/-1.33% BWxBH, respectively) during early stance as compared to controls (7.53+/-1.16% BWxBH). In the pain condition, PAD patients had a significantly reduced ankle plantar flexor moment (7.56+/-1.41% BWxBH) during late stance as compared to controls (8.65+/-1.27% BWxBH). Furthermore, when comparing PF to pain conditions, there was a decreased peak plantar flexor moment (PF condition: 8.23+/-1.37 vs. pain condition: 7.56+/-1.41% BWxBH) during late stance. The findings point to a weakness in the posterior compartment muscles of the hip and calf as being the key factor underlying the PAD gait adaptations. Our findings establish a detailed baseline description of the changes present in PAD patient's joint angles and moments during walking. Since IC is primarily a gait disability, better understanding of the abnormalities in joint and muscle function will enhance our understanding of the gait impairment and may lead to novel, gait-specific treatments.

Prevalence of and risk factors for peripheral arterial disease in the patients with hypertension among Han Chinese

OBJECTIVES

Peripheral arterial disease (PAD) is associated with morbidity and mortality of coronary heart disease and stroke. Hypertension is an independent risk factor for peripheral arterial disease. However, the prevalence and risk factors of PAD in hypertensive patients have not been studied in China.

METHODS

In order to investigate the prevalence of PAD and its risk factors in China, a cross-sectional study was carried out. A total of 4716 patients with hypertension and 833 age-gender matched people without hypertension were recruited; age 40 to 75 years, from seven rural communities. PAD was defined as an ankle-brachial index (ABI) <or= 0.9 in either leg; hypertension was defined as systolic blood pressure >or=140 mm Hg, diastolic blood pressure >or=90 mm Hg, or history of antihypertensive drug use.

RESULTS

The prevalence of PAD is 8.7% (n = 408) in patients with hypertension (n = 4716), higher than in people without hypertension (5.0%, n = 833, P = .004). Hypertensive patients with PAD were older, (61 +/- 8.6 vs 58 +/- 8.6, P < .01), had more conventional cardiovascular risk factors including systolic blood pressure (170 +/- 22.6 vs 167 +/- 22.7, P < .01), pulse pressure (72 +/- 19.7 vs 68 +/- 18.9, P < .01), blood glucose (5.8 +/- 2.2 vs 5.6 +/- 1.7, P < .05), total cholesterol (5.7 +/- 1.3 vs 5.5 +/- 1.1, P < .05), and serum uric acid (355 +/- 98.0 vs 293 +/- 86.2, P < .05) than the hypertensive patients without PAD. After adjusting for gender, age, and other cardiovascular risk factors by using multiple logistical regression analysis, PAD was still associated with current smoking (odds ratio [OR] = 1.65, 95% confidence interval [CI] 1.18-2.29), history of stroke (OR = 1.50, 95% CI 1.12-2.00), serum uric acid (OR = 1.21, 95% CI 1.10-1.59), and total cholesterol (OR = 1.12, 95% CI 1.10-1.59).

CONCLUSION

This study reports, for the first time, the prevalence of PAD in Chinese patients with hypertension, which is quite different from that in westerners, and that PAD is independently associated with conventional cardiovascular risk factors.

Distal lower extremity imaging: prospective comparison of 2-dimensional time of flight, 3-dimensional time-resolved contrast-enhanced magnetic resonance angiography, and 3-dimensional bolus chase contrast-enhanced magnetic resonance angiography

OBJECTIVE

To compare the 2-dimensional time of flight, the 3-dimensional time-resolved contrast-enhanced magnetic resonance (MR) angiography, and the 3-dimensional 3-station bolus chase contrast-enhanced MR angiography in assessing distal station atherosclerosis.

METHODS

Two-dimensional time of flight, 3-dimensional time-resolved contrast-enhanced MR angiography, and 3-dimensional bolus chase contrast-enhanced MR angiography were performed from the knees to the metatarsal heads of 40 patients. Blinded to the patients' identity, 2 readers independently reviewed the 3 sequences in random order; differences were resolved by consensus. Anterior tibial, peroneal, and posterior tibial arterial lengths to the talar dome were scored as follows: 1, greater than 50% of the length of a normal artery; 2, less than 50%; and 3, total occlusion. Stenoses were scored as follows: 1, less than 50%; and 2, greater than 50%. The pedal vessels (dorsalis pedis, posterior tibial, and plantar pedal arch arteries) were scored as follows: 1, less than 50% stenosis; and 2, greater than 50% stenosis. The reference standard was a combined interpretation of all 3 sequences by both readers in consensus.

RESULTS

For the 240 calf segments scored for length, concordance with reference assessment was poorer for the time of flight than for either the bolus chase or time-resolved angiography (P = 0.0021 and P = 0.0082, respectively), and the latter two were statistically indistinguishable. For stenosis grading of the 461 calf and pedal segments, the time-resolved and bolus chase methods were superior to the time of flight (P = <0.0001 and P = 0.0041, respectively), and the contrast-enhanced methods were statistically indistinguishable.

CONCLUSIONS

Both contrast-enhanced time-resolved and bolus chase MR angiography are superior to the time of flight in diagnosing distal station peripheral vascular disease.

Using ankle-brachial index to detect peripheral arterial disease: prevalence and associated risk factors in a random population sample

BACKGROUND AND AIM

The ankle-brachial index (ABI) is being used increasingly to diagnose peripheral arterial disease (PAD) that predicts cardiovascular morbidity and mortality. The aim of this study is to determine the prevalence of PAD and associated risk factors in a Spanish random population sample of age > or =40.

METHODS AND RESULTS

PAD is defined as an ABI<0.9 in either leg. 784 participants of age > or =40 were randomly selected in a Spanish province. 55.4% of them were female. The prevalence of PAD in this sample was 10.5% (95% confidence interval (CI) 8.4-12.8); 9.7% in females and 11.4% in males. In logistic regression analyses, adjusted for age and gender, smoking per 10 pack-years (odds ratio (OR) 1.40, 95% CI 1.23-1.58), hypertension (OR 1.85, 95% CI 1.05-3.28), hypercholesterolemia (OR 1.76, 95% CI 1.04-2.98), and diabetes (OR 1.80, 95% CI 1.04-3.11) were positively associated with prevalent PAD. More than 91% of persons with PAD had one or more cardiovascular disease risk factors.

CONCLUSIONS

We conclude that in our study hypertension, hypercholesterolemia, diabetes mellitus and smoking are associated with PAD. The majority of individuals with PAD had at least one important cardiovascular risk factor advanced enough to be considered eligible for an aggressive treatment.

Quality of Life and Peripheral Arterial Disease

Peripheral arterial disease (PAD) is a common disease entity with the potential to cause considerable impairment in the quality of life (QoL) of millions of Americans. As there is no exact cure for PAD, thus representing a chronic illness, the goal of treatment is disease management including the prevention of cardiovascular events, and improving QoL by helping people with PAD live productive and satisfying lives. Disagreement exists between patients' clinically inferred QoL status and their perceptions of QoL exist concerning PAD. Whereas a clinician may be concerned with a physiological or anatomical abnormality that may ultimately lead to disease and discomfort, a patient may be more concerned with their overall sense of QoL, which is only in part related to their clinical health status. Thus, to truly understand the outcomes of PAD and its treatment, it is necessary to supplement the traditional clinical outcome measures with information from the patient point of view. In this article, we review measurement instruments available to assess patient-reported QoL, and discuss the potential these tools have for providing accurate and meaningful information to complement traditional clinical outcome data.

Abnormal cardiovascular response to exercise in patients with peripheral arterial disease: Implications for management

Exercise is beneficial in improving claudication and functional capacity in patients with peripheral arterial disease (PAD). However, the physiologic response during and after exercise testing in this patient population has not been fully described. This study examined the cardiovascular response to exercise and explored the potential contribution of vascular noncompliance to exercise-induced hypertension in 124 patients with PAD and claudication and 31 comparison (C) patients with PAD with no walking limitations. Maximal walking distance was determined by an exercise treadmill test. Heart rate and blood pressure were monitored before, during, and immediately after an exercise test. Vascular compliance of the small and large vessels was measured using pulse waveform analysis. Individuals with low supine resting heart rate had longer pain-free walking distance (r = -0.195, P = .019) and maximal walking versus the C group (62 beats/min, standard deviation [SD] = 10, P = .02). Systolic blood pressure during supine rest was significantly lower for the PAD group (mean = 141 mm Hg, +/- SD = 22) versus the C group (mean = 153 mm Hg, +/- SD = 20, P = .003). Vascular compliance of large vessels was higher in the C group (mean = 4.13 +/- 4.13 mL/mm Hg x 100) compared with the PAD group (mean = 2.95 +/- 1.6 mL/mm Hg x 100). This study describes the exaggerated exercise cardiovascular response and impaired vascular compliance in patients with PAD. These results provide further evidence supporting the importance of a monitored treadmill exercise test before initiation of an exercise program to ensure safe and accurate exercise recommendations, and to identify individuals that require more intensive pharmacotherapy to prevent exercise-induced hypertension and tachycardia.

Effect of Warfarin Anticoagulation on Below-Knee Polytetrafluoroethylene Graft Patency

When polytetrafluoroethylene (PTFE) must be used for below-knee bypass to achieve limb salvage, effective anticoagulation with warfarin may improve graft survival. We analyzed our practice of routinely using oral anticoagulation to improve graft patency rates for PTFE grafts to below-knee popliteal and crural vessels in limb salvage procedures. We reviewed our established vascular database from February 1999 through April 2003 to identify those patients who required below-knee and tibial artery bypass with PTFE for critical limb ischemia. All patients were initiated on warfarin anticoagulation postoperatively, with an international normalized ratio (INR) of 2.0-3.0 considered therapeutic. All patients were discharged in the therapeutic range. Life-table analysis and Kaplan-Meier estimates were used to compare primary patency rates with regard to INR and position of distal anastomosis. Cox proportional hazards analysis was performed to compare the patency rates for grafts with therapeutic versus subtherapeutic anticoagulation while correcting for variability in distal runoff. Between February 1999 and April 2003, 74 patients (mean age, 69.2 years; 58% men) had 77 below-knee PTFE bypasses. Indications for operation included rest pain (43), ischemic ulcer (27), and gangrene (7). Patients presenting with occluded grafts more often had a subtherapeutic INR. Patients with a subtherapeutic INR (< or = 1.9) had a median primary graft patency of 6.8 months and those with a therapeutic INR (> or = 2.0) had a median primary graft patency of 29.9 months (p = 0.0007). Analysis by Cox proportional hazards model demonstrated a significantly better graft patency rate in patients with a therapeutic INR regardless of outflow vessel. The patency rates of PTFE grafts to infrageniculate vessels may be improved by effective anticoagulation with warfarin. This improved patency rate may also result in improved limb salvage and further support the use of PTFE grafts for critical limb ischemia when autogenous vein is not available. Predictably, the best results are seen with an INR therapeutic range of 2.0 to 3.0.

ORIGINAL RESEARCH—EPIDEMIOLOGY: Erectile Dysfunction Is a Marker for Cardiovascular Disease: Results of the Minority Health Institute Expert Advisory Panel

INTRODUCTION

Cardiovascular disease and its related comorbidities are associated with significant morbidity and mortality and affect a disproportionately large number of African Americans and Hispanics. The prevalence of cardiovascular disease is increasing worldwide, which underscores the urgency to improve methods of prevention and early detection.

AIM

To develop a risk assessment and management algorithm for primary care patients with erectile dysfunction (ED) that facilitates diagnosis, early intervention, and prevention of cardiovascular disease.

METHODS

The Minority Health Institute (MHI) convened an Expert Advisory Panel of cardiologists and urologists to design a new practice model algorithm that uses ED as a clinical tool for early identification of men with systemic vascular disease. A draft of the algorithm was presented at a national symposium and comments from symposium participants were considered in the development of the final algorithm.

MAIN OUTCOME MEASURES AND RESULTS

Erectile dysfunction is common and has long been considered a secondary complication of cardiovascular disease, diabetes, hypertension, and dyslipidemia. However, a growing body of evidence challenges this view, suggesting instead that ED is an early manifestation of atherosclerosis and a precursor to systemic vascular disease. Endothelial dysfunction is the etiologic factor linking ED and cardiovascular disease.

CONCLUSIONS

The recognition of ED as an early sign of systemic cardiovascular disease offers an opportunity for prevention, particularly in high-risk and underserved minority populations. The MHI algorithm stipulates that all men 25 years old and older regardless of sexual dysfunction complaints should be asked about ED. The presence of ED should prompt an aggressive assessment for cardiovascular risk and occult systemic vascular disease.