Systematic review/meta-analysis
A Meta-analysis of Randomized Controlled Trials Comparing Percutaneous Coronary Intervention With Medical Therapy in Stable Angina Pectoris

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Abstract

There continues to remain uncertainty regarding the effect of percutaneous coronary intervention (PCI) vs medical therapy in patients with stable angina. We therefore performed a systematic review and study-level meta-analysis of randomized controlled trials of patients with stable angina comparing PCI vs medical therapy for each of the following individual outcomes: all-cause mortality, cardiovascular (CV) mortality, myocardial infarction (MI), and angina relief. We used 8 strategies to identify eligible trials including bibliographic database searches of MEDLINE, PubMed, EMBASE, and the Cochrane Controlled Trials Registry until November 2011. Two independent reviewers undertook decisions about study eligibility and data abstraction. Data were pooled using a random effects model. Ten prospective randomized controlled trials fulfilled our eligibility criteria and they included a total of 6752 patients. We did not detect differences between PCI vs medical therapy for all-cause mortality (663 events; relative risk [RR], 0.97 [confidence interval (CI), 0.84-1.12]; I2 = 0%), CV mortality (214 events; RR, 0.91 [CI, 0.70-1.17]; I2 = 0%), MI (472 events; RR, 1.09 [CI, 0.92-1.29]; I2 = 0%), or angina relief at the end of follow-up (2016 events; RR, 1.10 [CI, 0.97-1.26]; I2=85%). PCI was not associated with reductions in all-cause or CV mortality, MI, or angina relief. Considering the cost implication and the lack of clear clinical benefit, these findings continue to support existing clinical practice guidelines that medical therapy be considered the most appropriate initial clinical management for patients with stable angina.

Résumé

L'incertitude concernant l'effet de l'intervention coronarienne percutanée (ICP) par rapport au traitement médical chez les patients ayant une angine stable demeure. Par conséquent, nous avons effectué une revue systématique et une méta-analyse d'essais aléatoires de patients ayant une angine stable en comparant l'ICP au traitement médical pour chacun des résultats individuels suivants : la mortalité toutes causes confondues, la mortalité cardiovasculaire (CV), l'infarctus du myocarde (IM) et le soulagement de l'angine. Nous avons utilisé 8 stratégies pour déterminer les essais admissibles incluant les recherches de bases de données bibliographiques de MEDLINE, de PubMed, d'EMBASE et du Registre des essais Cochrane jusqu'au mois de novembre 2011. Deux (2) examinateurs indépendants ont pris les décisions sur l'admissibilité de l'étude et l'abstraction de données. Les données ont été regroupées en utilisant un modèle à effets aléatoires. Dix essais aléatoires prospectifs remplissaient notre critère d'admissibilité et incluaient un total de 6752 patients. Nous n'avons pas détecté de différences entre l'ICP et le traitement médical en ce qui a trait à la mortalité toutes causes confondues (663 événements; risque relatif [RR], 0,97 [intervalle de confiance (IC), 0,84-1,12]; I2 = 0 %), la mortalité CV (214 événements; RR, 0,91 [IC, 0,70-1,17]; I2 = 0 %), l'IM (472 événements; RR, 1,09 [IC, 0,92-1,29]; I2 = 0 %) ou le soulagement de l'angine à la fin du suivi (2016 événements; RR, 1,10 [IC, 0,97-1,26]; I2 = 85 %). L'ICP n'a pas été associée aux diminutions de la mortalité toutes causes confondues ou CV, de l'IM ou du soulagement de l'angine. Considérant les conséquences du coût et le manque d'avantages cliniques clairs, ces résultats continuent de soutenir les lignes directrices existantes de la pratique clinique considérant que le traitement médical est la prise en charge clinique initiale des patients ayant une angine stable la plus appropriée.

Section snippets

Protocol

The protocol for trial identification, inclusion and data abstraction was specified a priori and is available upon request. All reviewers were mandated to follow this protocol, and we calculated agreement statistics for the trials included among the reports screened in this systematic review.

Eligibility criteria

We included only randomized controlled trials (RCTs) that assessed the effects of PCI (ie, balloon angioplasty alone, bare metal stent implantation, or drug-eluting stent implantation) compared with medical

Included trials

Figure 1 summarizes our search strategy. Our trial identification strategies identified 1123 citations. The screening process identified 17 citations that advanced to full text review. A total of 10 trials fulfilled eligibility criteria and were included in this systematic review. Overall eligibility agreement was excellent (κ = 0.91). One eligible trial was published in 2 separate reports; Angioplasty Compared to Medicine Evaluation (ACME)-1 and ACME-2 refers to trials that analyzed patients

Discussion

The principal finding of our meta-analysis of RCTs comparing PCI with medical therapy was that there was no significant difference in all-cause mortality, CV mortality, or MI between the 2 assigned initial management strategies. While clearly there was methodologic variability among trials because of the evolution of PCI over the long time horizon during which these trials were conducted and reported, it is noteworthy that the earlier trials performed in the early 1990s (ACME7, 8) and late

Conclusions

In summary, this meta-analysis has shown that there is no difference with respect to all-cause mortality, CV mortality, or the incidence of MI with an initial management strategy of medical therapy alone as compared with PCI plus medical therapy. Our findings also suggest that either strategy is equivalent with respect to angina relief at the end of follow-up, although the confidence of this finding is less certain. Our results continue to reinforce existing clinical practice guidelines that

Disclosures

The authors have no conflicts of interest to disclose.

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