Collaterals and the recovery of left ventricular function after recanalization of a chronic total coronary occlusion.

BACKGROUND

A good collateral function in patients with regional myocardial dysfunction may indicate viability with the potential for left ventricular (LV) recovery after revascularization of a chronic total coronary occlusion (CTO).

METHODS

A CTO (duration > 2 weeks) was successfully recanalized in 126 patients. During this procedure, the collateral function was assessed before the first balloon inflation by intracoronary Doppler and pressure wires. Collateral function indexes were calculated. Left ventricular function was assessed by the LV ejection fraction (LVEF) and the wall motion severity index (WMSI [SD/chords]). A repeat angiography was available in 119 patients after 4.9 +/- 1.4 m. An improvement of WMSI > or =1 SD/chord was considered significant.

RESULTS

Left ventricular function was normal in 42%, regional dysfunction with LVEF > or = 0.60 was observed in 16%, and regional dysfunction with LVEF < 0.60 in 42%. The former had a better collateral function than patients with LV dysfunction. In 39% of patients with LV dysfunction, a significant myocardial recovery was observed at follow-up. The collateral function was similar in patients with and without recovery. However, patients with recovery had a lower peripheral resistance as an indicator of a better preserved microvascular integrity.

CONCLUSIONS

Recovery of impaired LV function after revascularization of a CTO is not directly related to the quality of collateral function, as collateral development does not appear to require the presence of viable myocardium. However, a preserved microvascular integrity may be of relevance for myocardial recovery.