| Abstract: |
Background:Abrupt vessel closure is one of the worst events that can occur during PTCA.. It can lead to major complications like death, myocardial infarction and emergency coronary artery bypass graft. Abrupt closure incidence did not decrease over years inspite of improvement of the technology of PTCA and operator experience and this was assigned to broad expansion of the indications ofPTCA.Objectives:The aim of this work was to study the incidence of abrupt closure, define the different predictors of its occurrence and to highlight the modalities of itsMethods:Fourty three patients (group A) who developed abrupt closure in the period between May 1997 and June 1999 in our Laboratory were included in our study. Fifty five patients with successful PTCA (group B) done in the same period were randomly chosen and included in the study for comparison. The total number of PTCA done during this period was 994 patients. The Patients underwent full clinical examination, echocardiography and exercise stress test before performing PTCA. Coronary angiography was performed to evaluate the type, site, length and severity of the target lesion. Computer analysis was used to accurately measure the length and severity ofthe lesion. PTCA was done following the conventional techniques. The occurrence of abrupt closure. its mechanism, Procedural Predictors, sequalae and management were studied in detail for each patient. Clinical, angiographic and procedural predictors for abrupt closure were determined for every patient using mono variate and multivariate statistical analysis. Individual lesion scoring was calculated for each patient and the relationship between lesion score and percent prediction of abrupt closure was determined. The patients in both groups were followed up for 3-6 months with clinical evaluation, echocardiography, exercise stress test in symptomatic patients and coronary angiography if indicated.Results: The incidence of abrupt closure was 4.1% in our study, 95% of Patients had in-laboratory closure while 5% had out of-laboratory closure. It was found that female gender, unstable angina and hypertension were the strongest clinical Predictors of abrupt closure (P < 0.05). Considering the angiographic factors, lesion length, side branch involvement, right coronary location, total occlusion, Presence of thrombus and calcification form the strongest factors (P < 0.05). When ACC/ AHA classification for lesion types was applied; type C lesions strongly predicted abrupt closure (P = 0.03). Abrupt closure was more prevalent in multi lesion PTCA compared to single lesion PTCA (P < 0.06).Dissection was the mechanism of abrupt closure in 68% of patients, elastic recoil caused closure in 19% of patients, newly formed thrombus was found in 9% of patients while persistent spasm occurred in one patient (2%), and in another patient the mechanism was unknown. For management of abrupt closure, successful repeateddilation was applied in 10% of patients (4 patients) & (Perfusion balloon was used in one patient of them); streptokinase was given to 5% of patients (2 patients). Glycoproten lIB, IlIA inhibitor was given successfully to another patient (2%). [ntracoronary stents were applied in 59% of patients. The primary success rate was 83% and 50% of these stented patients were asymptomatic at follow up period. Emergency CABG was performed in 19% of patients of whom 50% developed acute myocardial infarction and 25% developed Post-operative death. Acutely following abrupt closure, Qwave myocardial infarction occurred in 9% of patients and nonQwave myocardial infarction complicated 7% of patients and 5 patients (12%) died.At follow up period, patients with abrupt closure had a trend toward poorer prognosis with more deaths (7% versus 0% in non-closure group), myocardial infarction (9% versus 4% in non-closure group) and (left ventricular failure 5% versus 3% in non-closure group).Echocardiography at follow up period revealed more deterioration of left ventricular systolic function in closure groups compared to non-closure group (46% versus 20%) (P=0.0094).Restenosis rate was less in closure group (12%) compared to non-closure group (24%) due to liberal use of stents to manage abrupt closure.
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