Medial artery calcification in peripheral artery disease

Medial artery calcification (MAC) is a distinct, highly regulated process that is often identified in small and mid-sized arteries of the lower extremities. It is associated with advanced age, diabetes, and chronic kidney disease. MAC often occurs in conjunction with atherosclerotic occlusive disease in lower extremity arteries, and when seen together or in isolation, long-term limb outcomes are negatively affected. In patients with peripheral artery disease (PAD), the extent of MAC independently correlates with major amputation and mortality rates, and it predicts poor outcomes after endovascular interventions. It is associated with increased arterial stiffness and decreased pedal perfusion. New endovascular methods aimed at treating calcified lower-extremity lesions may improve our ability to treat patients with limb-threatening ischemia. Although recent developments have increased our understanding of the mechanisms contributing to MAC, further investigations are needed to understand the role of medial calcification in PAD, and to develop strategies aimed at improving patient outcomes.

Peripheral arterial disease and hypertension

PURPOSE OF REVIEW

Hypertension (HTN) is a well known risk factor for atherosclerosis and peripheral arterial disease (PAD). PAD affects more than 250 million people globally and is associated with worse clinical outcomes. Although multiple studies have been performed to evaluate treatment of HTN in patients with PAD, blood pressure management in this high-risk cohort remains poor.

RECENT FINDINGS

There has been conflicting evidence regarding blood pressure goals in PAD with some recent studies showing adverse outcomes with low blood pressure in this patient population. Current guidelines, however, continue to recommend treatment goals in PAD patients similar to patients without PAD. To date, no single antihypertensive drug class has shown a clear benefit in PAD population over other antihypertensive drug classes.

SUMMARY

Prospective randomized trials enrolling PAD patients are required that can shed light on optimum blood pressure target and also distinguish between different antihypertensive drugs in terms of reducing adverse outcomes.

Risk factors associated with amputation-free survival for patients with peripheral arterial disease: a systematic review

AIMS

Peripheral arterial disease (PAD) is associated with morbidity and mortality, comprising a significant percentage of amputations. As it affects the quality of life of patients with PAD, it is an important health issue. Therefore, the risk factors affecting the outcomes of limb salvage after revascularization should be well investigated. The aim of this review is to summarize risk factors of amputation-free survival (AFS) after interventions targeting patients with PAD to develop evidence-based intervention for improving patient outcomes.

METHODS AND RESULTS

A systematic review following PRISMA guidelines was conducted, and the protocol was registered on PROSPERO (CRD42020183076). PubMed, CINAHL, EMBASE, Cochrane Library, and Web of Science were searched for observational studies published between 2008 and 2019. Search terms included 'peripheral arterial disease', 'risk factors', and 'amputation-free survival'. The quality of the studies was evaluated using the Joanna Briggs Institute's Critical Appraisal Tools. Seventeen cohort studies were included in our study, and 16 risk factors were identified. Risk factors exemplifying a significant influence on decreased AFS were divided into three categories: sociodemographic (e.g. older age, male gender, African-American race, low body mass index, high nutritional risk, frailty), disease-related characteristics (e.g. severity of the disease, intervention site), and comorbidities (e.g. cardiovascular disease, kidney disease, diabetes mellitus, chronic obstructive pulmonary disease, dementia, wide pulse pressure).

CONCLUSION

We found that managing modifiable risk factors, as well as addressing high-risk populations, has the potential to improve outcomes of PAD interventions. More high-quality cohort studies are needed to confirm these findings.

Preoperative Pulse Pressure and Adverse Postoperative Outcomes: A Meta-Analysis

OBJECTIVE

To evaluate the association between preoperative pulse pressure (PP) and the incidences of renal, neurologic, cardiac, and mortality outcomes after surgery.

DESIGN

Systematic review and meta-analysis of cohort studies.

SETTING

Hospitals.

PARTICIPANTS

Patients who underwent cardiac or noncardiac surgeries.

INTERVENTION

The preoperative PP was measured.

MEASUREMENT AND MAIN RESULTS

Relevant cohort studies were obtained by systematic search of PubMed and Embase databases. A randomized effect model was used to pool the results. The multivariate adjusted risk ratio (RR) and its 95% confidence intervals (CI) were calculated to reflect the association between preoperative PP and adverse postoperative outcomes. Twelve cohort studies that included 40,143 patients who had undergone cardiac, vascular, or noncardiac surgery were included in the meta-analysis. The results showed that above a threshold of 40 mmHg, an increase in preoperative PP of 10 mmHg was independently associated with increased risk for renal events (adjusted RR: 1.13, 95% CI 1.08-1.19, p < 0.001; I² = 0%), neurologic events (adjusted RR: 1.75, 95% CI 1.01-3.02, p = 0.04; I² = 70%), cardiac events (adjusted RR: 1.19, 95% CI 1.03-1.37, p = 0.01; I² = 0%), major cardiovascular adverse events (adjusted RR: 1.62, 95% CI 1.10-2.41, p = 0.02; I² = 0%), and overall mortality (adjusted RR: 1.13, 95% CI 1.07-1.20, p < 0.001; I² = 0%) after surgery.

CONCLUSIONS

Patients with higher-than-normal preoperative PP are at increased risk for adverse postoperative outcomes.