Coronary Stenting for Non-Acute Coronary Disease Compared to Medical Therapy
Benefits in NNT
None were helped (life saved, heart attack prevented, symptoms reduced)
100% saw no benefit
0% were helped by being saved from death
0% were helped by being saved from a heart attack
0% were helped by having less angina (chest pain)
Harms in NNT
1 in 50 were harmed (complications such as bleeding, stroke, kidney damage)
2% were harmed by procedure complications
SourceStergiopoulos K, Brown DL. Initial coronary stent implantation with medical therapy vs medical therapy alone for stable coronary artery disease: meta-analysis of randomized controlled trials. Arch Intern Med. 2012;172(4):312-9
Efficacy EndpointsDeath, nonfatal myocardial infarction, angina symptoms
Harm EndpointsProcedural complications such as bleeding, stroke, kidney damage, death
NarrativePercutaneous coronary interventions (typically stents) are used hundreds of thousands of times each year to open narrowed coronary arteries. Most such patients are not in the midst of an acute coronary syndrome such as a heart attack. This meta-analysis aimed to determine whether stenting (i.e. opening) as an initial approach to narrowed arteries is more beneficial than simply taking medicines to prevent future attacks or death.
Over 7000 patients with coronary narrowing were included from eight trials in which patients were randomly assigned to receive either stents plus optimal medical therapy, or optimal medical therapy alone (i.e. without stents). The studies were generally high quality and the results appear robust, suggesting that medical therapy without stenting is as effective at preventing deaths, heart attacks, and symptoms as the placement of coronary stents.
CaveatsPrior meta-analyses examining this topic have come to differing conclusions on this and similar questions, in some cases suggesting benefits to stenting,1 2 and in other cases suggesting no benefit.3 The differences are likely attributable to variations in the included studies. A strength of this review, and the reason we have given it primacy in our summary, is that studies chosen for this review best represent both stenting and medical therapy in their current form. In other words many prior studies used older methods (ballon angioplasty, etc.) for coronary opening, and in many studies patients receiving medical therapy did not receive the recommended pill regimens that contemporary CAD patients receive. Therefore this review appears to best represent a proper comparison of current PCI versus current medical therapy.
PCI and the coronary angiography that necessarily precedes PCI are both invasive procedures with harms. Morbidity from these procedures has been poorly documented and inadequately studied in a contemporary milieu, thus harm numbers are best-guess estimates, however it is widely accepted that major complications include stroke, kidney failure, heart attack, and death.4 5 The American Heart Association suggests that 2% of patients, or 1 in 50, suffers an important complication.6
It is also important to recall that coronary artery bypass graft surgery appears to benefit a small number of patients and PCI has in many cases become a less risky replacement for this surgery. Such cases are often patients with specific, severe patterns of coronary narrowing, or patients who are poor surgical candidates. However the studies in this review excluded such patients. Thus there will be cases of nonacute coronary disease for which PCI is appropriate or beneficial, and this review does not apply to such patients.
For the patients in this group of studies, however, who appear to represent the majority of patients currently eligible for PCI, there was no identifiable benefit to the procedure and there are established harms. While the frequency of these harms is not clear, their existence is, thus we have chosen to classify this intervention as ‘Black’.
AuthorDavid Newman, MD
Published/UpdatedJune 18, 2012
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Wijeysundera HC, Nallamothu BK, Krumholz HM, Tu JV, Ko DT. Meta-analysis: effects of percutaneous coronary intervention versus medical therapy on angina relief. Ann Intern Med. 2010 Mar 16.152(6):370-9
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