Is Peripheral Artery Disease (PAD) mortality the same as Coronary Artery Disease (CAD) mortality?

PAD Mortality vs CAD Mortality

Patients with PAD have significantly higher mortality rates compared to patients with CAD, with all-cause mortality approximately 3.1 times greater and cardiovascular mortality 5.9 times greater in PAD patients compared to those without PAD. 1

Comparative Mortality Data

PAD Mortality Risk

• In the Framingham Study, mortality in patients with intermittent claudication was 2-3 times higher than age- and sex-matched controls, with 75% of PAD patients dying from cardiovascular events 1
• A 10-year prospective study by Criqui et al. showed PAD patients had 3.1 times greater all-cause mortality and 5.9 times greater cardiovascular mortality compared to patients without PAD 1
• The 5-year mortality rate with active smoking and chronic symptomatic PAD is 40%-50% 1

PAD vs CAD Direct Comparisons

• Patients with PAD have worse long-term prognosis with an increased risk for all-cause mortality (hazard ratio=2.95) compared to CAD patients following first vascular intervention 2
• Even after multivariable analysis adjusting for risk factors, PAD patients maintain a significantly higher mortality risk (adjusted hazard ratio=1.86) compared to CAD patients 2
• In patients with both conditions, PAD significantly worsens CAD outcomes - patients with multivessel CAD and PAD had a 4.9 times greater relative risk of death compared to those with CAD alone 1
• A pooled analysis of 8 randomized trials showed 1-year mortality was 5% in patients with PAD and coronary disease compared with 2.1% in patients with coronary disease alone (p<0.001) 1

Risk Amplifiers in PAD

Several factors significantly increase mortality risk in PAD patients:

• Polyvascular disease: Patients with both PAD and CAD have a higher risk of all-cause death over 5 years (adjusted HR: 1.35) compared to those with only CAD 1
• Diabetes: Associated with higher risk of all-cause death (HR: 1.35) and major adverse cardiovascular events (HR: 1.47) 1
• Chronic kidney disease: Associated with higher rates of cardiovascular death, MI, and ischemic stroke (adjusted HR: 1.45) 1
• End-stage kidney disease: 5-year survival rate among those with PAD after renal transplantation is only 19% vs 48% in those without PAD 1
• Ongoing smoking: Dramatically increases PAD-related hospitalizations and mortality 1

Pathophysiological Explanation

The higher mortality in PAD compared to CAD can be explained by:

1. Systemic nature of atherosclerosis: PAD represents more widespread atherosclerotic disease affecting multiple vascular beds 3
2. Undertreatment: PAD patients receive less cardioprotective medications (statins, ACE inhibitors/ARBs, antiplatelet agents) compared to CAD patients 2, 4
3. Late diagnosis: More than 70% of primary care providers are unaware of PAD in their patients who have the disease 1
4. Asymptomatic presentation: Up to 50% of PAD patients are asymptomatic, leading to delayed diagnosis and treatment 1

Clinical Implications

• PAD should be recognized as a marker of extremely high cardiovascular risk, even higher than isolated CAD
• Aggressive risk factor modification is critical in PAD patients, particularly for hypertension and diabetes which are independent predictors for the presence of both CAD and PAD 5
• The severity of CAD affects prognosis in PAD patients - those with triple-vessel CAD have significantly worse outcomes than those with less severe or no CAD 6
• Inflammatory biomarkers appear to be the strongest risk factor contributing to excess cardiovascular risk in PAD patients 7

Common Pitfalls in PAD Management

• Undertreatment: Despite overwhelming evidence of increased risk, PAD patients often don't receive antiplatelet therapy or statins with the same frequency as CAD patients 1
• Focus on symptoms only: Treatment should address both quality of life impairment and the markedly increased cardiovascular risk 1
• Missing asymptomatic disease: Since up to 50% of PAD patients are asymptomatic, screening with ABI in high-risk populations is essential 1
• Overlooking depression: Comorbid depression in PAD is associated with 13% higher amputation rates and 17% higher mortality 1

In conclusion, PAD represents a significantly higher mortality risk than CAD, and this difference persists even after adjusting for traditional cardiovascular risk factors. This underscores the importance of aggressive risk factor management and appropriate medical therapy in all PAD patients, regardless of symptom status.