Abstract: | The aim of this study was to assess whether active coronary perfusion catheters (APC) can provide a sufficient coronary flow in large caliber vessels during balloon inflation. To prevent myocardial ischemia during PTCA, these APC may be employed. However, it is as yet unknown whether the active flow rate of these devices approaches the flow rate prior to PTCA during balloon inflation. Therefore, we measured the efficacy of the APC during balloon inflation in vessels supplying a large amount of myocardium. In 12 patients (1 female, 11 males, 53 ± 12.6 yr) with stenosed vessels (average diameter 3.4 ± 0.26 mm), the coronary flow velocity was measured using a 0.014“ Doppler guidewire, which was placed distally bypassing the balloon of the APC. The active perfusion balloon catheter was advanced through a 7F guiding catheter along a 0.014” guidewire. After removal of the guidewire, arterial blood being withdrawn from the side port of the femoral angioplasty sheath was pumped through the catheter to the distal coronary vessel. The perfusion volumes of the pump were set to different levels between 30 to 60 ml/min. Intracoronary flow rate was calculated by the angiographically assessed vessel luminal area × average peak velocity × 0.5. The mean coronary flow rate prior to PTCA was 43 ± 17.7 ml/min. Maximum flow during PTCA was 55 ± 19.6 ml/min. We found a good correlation between the preset external pump rate and the coronary flow in situ (r=0.92). Pre-PTCA flow rates were achieved in 11 of 12 patients (92%) during balloon inflation. No relevant decrease in the arterial pressure occurred during dilation times of 4.6 ± 1.63 min. Only two patients showed significant ECG changes during these balloon inflations. After an average follow-up period of 13 ± 6.3 mo, only one patient (8%) had a significant re-stenosis requiring the implantation of a stent. The combination of intravascular Doppler velocity measurements with quantitative coronary angiography offers the opportunity of exact online flow registration during angioplasty. Using APC, it is possible to maintain a sufficient coronary flow in the distal vessel during balloon inflation even in large vessels. Therefore, as compared with mechanical circulatory assist devices, coronary assist by APC is a little invasive, but according to our measurements it might be a sufficient tool for performing PTCA also in high-risk patients. Cathet. Cardiovasc. Diagn. 42:84-89, 1997. © 1997 Wiley-Liss, Inc. |