ABSTRACT
Percutaneous coronary intervention (PCI) has been associated with excessive radiation exposure, so the present study was designed to investigate the determinants of fluoroscopic time during PCI among characteristics inherent to the patient, procedure and hospital in 388 consecutive patients between November 1996 and March 1999 in 11 hospitals included in the Nationwide Database for Cost Analysis of percutaneous transluminal coronary angioplasty in Japan. Fluoroscopic time, which reflects radiation exposure, was used as the dependent variable in a multiple linear regression analysis. The mean fluoroscopic time was 27+/-15 min. The negative value of partial correlation of the hospital code (r=-0.374) and acute myocardial infarction (-0.163) indicated that these were explanatory variables that decreased fluoroscopic time. The positive value of the number of intraaortic balloon pump catheters (r=0.144), the number of balloons (r=0.304) and hospital stay (r=0.147) indicated these were explanatory variables that increased fluoroscopic time. The absolute value of r, (r=0.374), of the hospital code was the highest. In the final R(2) (=0.304) of the model, which is the partial R-square that determined the dependent variable, the hospital code showed the highest value. In conclusion, there was an inter-hospital difference in fluoroscopic time. Although the hospital code was found to be the most powerful determinant of fluoroscopic time, the R(2) (=0.304) of the model showed so lower value that other hospital characteristics that were not included in the model may influence the fluoroscopic time.
Subject(s)
Angioplasty, Balloon, Coronary , Coronary Angiography , Databases, Factual , Fluoroscopy , Aged , Angioplasty, Balloon, Coronary/economics , Cost-Benefit Analysis , Female , Humans , Japan , Linear Models , Male , Middle Aged , Radiation Dosage , Time FactorsABSTRACT
Although previous studies have demonstrated that even quantitative coronary angiography (QCA) can not provide accurate disease morphology, there has not been a systematic comparison of disease morphology determined by QCA and intravascular ultrasound (IVUS), particularly in Japanese patients. Therefore, the present study prospectively examined patients in a multicenter cooperative study. A total of 491 coronary sites from 562 patients (446 men, 116 women; mean age, 64+/-11 years) who underwent coronary interventions were enrolled. The target lesions (>50% diameter stenosis) were evaluated pre-operatively by both QCA and IVUS operating at 30-40 MHz and the percent area stenosis, eccentricity index (EI) and lesion length were determined. The minimal (min) and maximal (max) distances from the center of the stenotic lesion to the outline of the vessel wall were measured, and the EI was calculated by the formula: [(max - min)/max]. By QCA, lesion length was determined by measuring the distance between the proximal and distal shoulders of the lesion. When the lesions were observed by IVUS with a motorized pull-back system, the length was calculated by multiplying the time for observation of the disease and 0.5 or 1 mm/s. Although the severity of the stenosis determined by QCA (86+/-10%, mean +/- SD) did not differ from that by IVUS (83+/-13%), there was no correlation between them (r=0.32, y=0.25x+65) and the correlation did not improve when lesions with remodeling, enlargement (n=176) or shrinkage (n=79) were omitted from the calculation. The EIs by QCA and IVUS were 0.51+/-0.26 and 0.52+/-0.22, respectively (NS), and there was no correlation between them (r=0.30, y=0.36x+33). However, when the lesions with remodeling were excluded, the correlation greatly improved (r=0.80, y=0.84x+10.6, p<0.05). Lesion length determined by QCA (12.4+/-6.1 mm) was significantly shorter than that by IVUS (16.3+/-8.9 mm, p<0.01). These results demonstrate that coronary angiography significantly misinterprets disease morphology in terms of severity, eccentricity and length, in part because of vessel remodeling that can be accurately determined only by IVUS.
