Effect of collaterals on deaths and re-infarctions in patients with coronary artery disease: a meta-analysis

Abstract

Background It is generally believed that there is a beneficial effect of collaterals on death and re-infarction statistics in patients with coronary artery disease (CAD) but studies to date are small and inconsistent. Objective To meta-analyse the studies published in this field in order to obtain more powerful information. Methods We searched Medline and major journals (2000 to 2011) for studies evaluating the effect of coronary collaterals on mortality. Publication bias, lack of heterogeneity, and lack of robustness were assessed using the standard procedures for such purposes. Results A total of 10 studies describing mortality, enrolling 6791 participants, were included in this analysis. In patients with collateralisation a significant relation with reduced mortality was seen compared with those without collateralisation, at an odds ratio of 0.47, p<0.0001, and a reduction in deaths and re-infarctions at 0.54, p<0.0001. Some publication bias, some heterogeneity and some lack of robustness were demonstrated. A meta-regression with the odds ratios of the presence of traditional atherosclerotic risk factors as predictors and the odds ratios of mortality and the composite deaths and re-infarctions as outcome showed no relationships.Conclusions In CAD patients from the post-percutaneous coronary intervention era the presence of collaterals reduced mortality by 0.47 (p<0.0001) and deaths and re-infarctions by 0.54 (p<0.0001). Furthermore, in the present meta-data, the atherosclerotic risk factors were no more present in patients with collaterals than they were in those without.

Evaluation of the Prevalence of Cardiovascular Events and Mortality in Stable Coronary Heart Disease Patients Depending on Baseline Coronary Collateral Blood Flow (Five Year Follow-Up)

“…Однако исследования, вошедшие в мета-анализ, включали как больных со стабильной ИБС, так и больных с острым ИМ [9].…”

“…Считается, что видимые при коронароангиогра-фии (КАГ) коллатерали ассоциированы с меньшей зоной инфаркта миокарда (ИМ) [5], лучшей сократи-мостью левого желудочка [6] и меньшей частотой сердечно-сосудистых осложнений в будущем как у пациентов с ИМ, так и со стабильной ИБС [7][8][9].…”

“…На настоящий момент проведено лишь небольшое число исследований, направленных на изучение дан-ной взаимосвязи у больных со стабильной ИБС, более того, их результаты противоречивы [9]. Согласно данным ряда работ, тяжесть ИБС, а также степень поражения коронарного русла прямо про-порционально связаны со степенью развития ККК [10], соответственно, группа с более выраженными коллатералями чаще представлена пациентами более высокого риска, что в свою очередь может значимо повлиять на результаты исследований.…”

The impact of the coronary collateral circulation on outcomes in patients with acute coronary syndromes: results from the ACUITY trial

“…A low CFI was associated with a higher mortality 18. Another, more recent meta-analysis by Akin et al confirmed these findings and showed that the presence of collaterals reduces mortality as well as re-infarction 19. However, a major limitation of both meta-analyses is the lack of adjustment for potential confounding variables.…”

Coronary collaterals: an elusive network

“…Second, results are corrected for several important variables which may influence mortality in ACS. Previous studies, including meta-analyses,7 failed to adjust their findings for potential confounding factors. Indeed, after multivariable analysis, no significant difference was found in the present study by Meier et al between patients with and without collaterals in terms of 1-year mortality, MI and target vessel revascularisation.…”