PROGRESSION OF CORONARY-ARTERY DISEASE IN NONDILATED SITES IN THE MONTHS FOLLOWING BALLOON ANGIOPLASTY - TIME-DEPENDENT RELATION WITH RESTENOSIS

There is scant information on the progression of coronary artery disea se in non-dilated sites in the months following percutaneous translumi nal coronary angioplasty (PTCA) or on its relationship with restenosis . To assess the incidence of this progression and its relationship wit h restenosis at various times after PTCA, the authors selected 371 con secutive patients who had undergone a first successful PTCA for angina on native coronaries followed by a repeat angiographic study. The ang iograms were analysed by a computer-assisted method; progression was d efined as a 20% decrease in diameter and restenosis as a 30% decrease in diameter or a return to > 50% stenosis. The relationship between pr ogression and restenosis was analysed in the whole population and then , using the Mantel-Haenszel chi-square test, in two subgroups: patient s with a stable clinical state, who were restudied routinely and those whose worsened state had prompted repeat angiography. The relationshi p was assessed at different times between angioplasty and the repeat a ngiography. Progression was observed in 80 patients (22%) and restenos is in 155 patients (42%). There was a highly significant relationship between progression and restenosis in the total population (chi(2) = 2 6.4, odds ratio = 3.9 and P < 0.0003) and in the group of patients tha t were routinely restudied (chi(2) = 31.6, odds ratio = 5.3 and P < 0. 0001), but not in the group of patients in whom restudy was performed because of clinical worsening (chi(2) = 0.13, odds ratio = 1.5 and P = NS). With respect to the length of follow-up, in the total population the relationship was significant only at 6 and 7 months (P < 0.0001), and in the group receiving a routine restudy only at 4-5 and 6-7 mont hs (P < 0.001). Progression in non-dilated sites appeared to be strong ly and transiently linked with restenosis, suggesting that PTCA may en hance both restenosis and progression over a short period.