INFLUENCE OF MAXIMUM INFLATION PRESSURE A ND BALLOON SIZE ON DISSECTIONS COMPLICATING PERCUTANEOUS TRANSLUMINAL CORONARY ANGIOGRAPHY

Overstretching of the vessel wall, which leads to large dissections du ring PTCA, generally is dependent on the inflation pressure and the ba lloon diameter. The aim of our study was to assess, to what extent the maximum inflation pressure (MIP) and the balloon-to-artery-ratio (B-A -R) contribute to the incidence of large dissections complicating coro nary angioplasty. We studied the records and angiograms of 1017 consec utive patients who underwent PTCA with a MIP of less than or equal to 6 atm (group A:n = 728) or greater than or equal to 10 atm (group B:n = 289). Thus, we obtained the number of inflations (IN), total inflati on time (IT), procedural success (PS) and the incidence of angiographi c (dissection, total occlusion) and clinical complications [emergency CAB G, Q-wave infarction (MI)] in group A and group B patients. There was no significant difference between both groups in patient character istics and lesion morphology pre-PTCA. The mean balloon diameter and t he B-A-R were significantly higher, the residual stenosis (A:27+/-18%B :39+/-12%,p<0.05) statistically significant lower in group A than grou p B. PS, IN and IT were similar for both groups. The incidence of diss ections (A:15.2%;B:7.5%;p<0.01), occlusions (A:7.4%:B: 3.2%1p<0.03), n eed for CABG and MI were higher in group A than group B. The MIP of pa tients with complications were lower than the MIP of patients without complication (p<0.03), the B-A-R in patients with clinical complicatio ns higher than in those without (p<0.05). In conclusion, high MIP do n ot increase the incidence of large dissections complicating PTCA as fa r as the B-A-R does not exceed a value of 1:1. The main mechanism lead ing to large dissections is dilatation with an oversized balloon. In h igh-risk PTCA or great area-at-risk, increasing the balloon size to op timize the angiographic result should be avoided, because oversizing m ay lead to angiographic and clinical complications.