Do coronary stents reduce cardiac mortality or merely reduce symptoms?

Coronary Stents: Impact on Cardiac Mortality vs. Symptom Relief

Coronary stents primarily reduce symptoms in stable coronary artery disease but do not significantly reduce cardiac mortality except in specific high-risk scenarios such as acute myocardial infarction. 1, 2, 3

Impact on Mortality

Stable Coronary Artery Disease

• Coronary stenting in stable coronary artery disease has not been shown to provide a consistent mortality benefit compared to optimal medical therapy 2, 3
• Meta-analyses indicate that coronary stents (both bare-metal and drug-eluting) do not reduce total mortality when compared with medical therapy in stable coronary disease 4
• In contrast, coronary artery bypass grafting (CABG) has demonstrated a reduction in mortality risk compared to optimal medical therapy (OR = 0.84; 95% CI: 0.71-0.97), particularly in patients with extensive coronary disease 2

Acute Coronary Syndromes

• In acute myocardial infarction, primary PCI with stenting has shown mortality benefits compared to fibrinolytic therapy (5.9% vs 7.7%, OR 0.75,95% CI 0.60 to 0.94) 1
• Stent implantation in unstable coronary artery disease helps to mechanically stabilize disrupted plaque, which is particularly beneficial in high-risk lesions 1
• The mortality rate associated with percutaneous coronary intervention in acute settings is generally very low 1

Impact on Symptoms

Symptom Relief

• PCI with stenting consistently demonstrates superior control of angina symptoms compared to medical therapy alone 1
• The RITA-2 trial showed that PCI results in better control of symptoms of ischemia and improved exercise capacity compared with medical therapy 1
• In the AVERT trial, angina relief was greater in patients treated with PCI compared to those on medical therapy, even though ischemic events were lower in the medically treated group 1

Quality of Life Improvements

• Stenting improves quality of life by reducing angina and increasing exercise capacity 1
• These symptomatic benefits are particularly evident in patients with single-vessel disease 1
• However, PCI may be less effective in controlling symptoms in patients with double-vessel disease compared to single-vessel disease 1

Stent Types and Outcomes

Bare-Metal vs. Drug-Eluting Stents

• Drug-eluting stents (DES) show consistently better treatment effects compared to bare-metal stents (BMS), reducing restenosis and major adverse cardiac events including target vessel revascularization 1
• Coronary stenting reduces the rate of restenosis and the need for repeat PCI compared to balloon angioplasty alone 1
• However, concerns have been raised regarding the long-term safety of DES, particularly regarding late stent thrombosis 1
• Some evidence suggests that sirolimus-eluting stents may be associated with increased non-cardiac mortality at 2-3 years of follow-up 4

PCI vs. CABG

• For multivessel disease, CABG has shown a mortality benefit compared to PCI at 5-8 years, as well as significantly less angina and less need for repeat revascularization 1
• In non-diabetic patients with one to two vessel disease without high-grade stenosis of the proximal LAD, PCI is generally the preferred initial approach 1
• For left main coronary artery disease, early observational studies demonstrated poor prognosis with medical therapy alone (3-year survival rates of 50%) 1
• CABG has historically provided survival benefit to patients with >50% left main coronary artery stenosis compared to medical therapy 1

Clinical Implications and Recommendations

• For acute coronary syndromes, particularly STEMI, stenting offers mortality benefits and should be preferred when timely access is available 1
• For stable coronary artery disease, stenting should be considered primarily for symptom relief when medical therapy is inadequate 1, 3
• In high-risk anatomical scenarios (left main disease, multivessel disease, especially in diabetics), CABG may offer mortality benefits over stenting 1, 2
• The choice between PCI and CABG should consider factors such as anatomical complexity, comorbidities, and patient preferences 1

Common Pitfalls

• Assuming stents provide mortality benefit in all scenarios when evidence supports this primarily in acute settings 3
• Underestimating the importance of optimal medical therapy, which should be the foundation of treatment for stable coronary disease 2, 3
• Failing to consider the higher risk of repeat revascularization with PCI compared to CABG, particularly in complex disease 1
• Not maintaining adequate antiplatelet therapy after stenting, which is crucial for preventing stent thrombosis 1, 5