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13-10-2011 | Cardiology | Article

Assessing coronary collateralization may be useful for risk stratification in CAD


Free abstract

MedWire News: Coronary artery disease (CAD) patients with high coronary collateralization have a significantly lower mortality risk than those with low collateralization, a meta-analysis suggests.

Assessment of coronary collateralization could provide useful information when risk stratifying CAD patients who are undergoing angiography, report Christian Seiler (University Hospital Bern, Switzerland) and colleagues in the European Heart Journal.

Collateral coronary arteries have the potential to remodel and expand after stenosis and provide an alternative blood supply to damaged myocardium, they explain. They therefore decided to investigate whether collateralization impacts mortality in patients with stable or acute CAD.

The meta-analysis included 6529 participants across 12 studies conducted between 2001 and 2011.

The results showed that patients with high collateralization (defined as any collaterals visible upon coronary angiogram, Rentrop score 1-3; or collateral flow index [CFI] ≥0.25) had a 36% lower risk for all-cause mortality than those with low collateralization (no collaterals visible, Rentrop score 0; or CFI >0.25; p=0.012).

Subgroup analysis showed that patients with stable disease and high collateralization had a beneficial effect in terms of all-cause mortality (risk ratio=0.59, p=0.012) as did those with unstable disease, but this particular association did not reach statistical significance.

The beneficial effect of coronary collaterals was more pronounced in studies where the majority of patients underwent percutaneous coronary intervention (PCI) compared with studies without PCI, note the authors.

"The coronary collaterals may represent a useful prognostic marker," they remark. "Patients with a low collateralization may have an increased mortality risk and [should] be monitored more closely."

Coronary collateralization could be improved by promoting arteriogenesis with growth factors GM-SF and G-CSF or with external counterpulsation, they add.

Seiler and team conclude: "The therapeutic indication of collateral growth may have significant implications on outcomes."

MedWire ( is an independent clinical news service provided by Current Medicine Group, a trading division of Springer Healthcare Limited. © Springer Healthcare Ltd; 2010

By Piriya Mahendra

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