Predictors of insistent restenosis in patients undergoing percutaneous intervention
Authors:   , Amod Ameena 
Published: October 2022

Coronary artery disease is one of the leading causes of morbidity and mortality worldwide. The first percutaneous coronary intervention was performed by Andreas Gruntzig on September 16, 1977. This procedure was performed on patients with arterial stenosis. The limitations of angioplasty, however, included an unpredictable acute result- due to early abrupt vessel closure- and relatively high rate of restenosis at the site of the treated lesion- due mainly to plaque prolapse, vessel recoil, and constrictive remodelling. A vessel without a stent can have restenosis due to vessel remodelling as well as elastic recoil. Drug eluting stents have helped in the reduction of in-stent restenosis, but this still poses a problem for interventional Cardiologist. Instent restenosis is an independent predictor for mortality during follow up, together with other relevant clinical factors as age, sex, diabetes mellitus, smoke habit, previous bypass surgery, and left ventricular ejection fraction. Restenosis is not random; certain patients seem to present with this complication, having a better understanding of this phenomenon would be useful to save on financial cost of interventional cardiology as a result of adjuvant medication and devices. To establish the exact incidence of restenosis is not easy, it depends on a number of different factors and variables. These include patient related factors, lesion related and procedure related. Drug eluting stents tend to drastically reduce the occurrence of severe neo-intimal proliferation, which is the dominant cause on in-stent restenosis. Optical coherence tomography (OCT) and intravascular ultrasound (IVUS) have played an important role in assisting with real time imaging of in-stent restenosis. Nevertheless, drug eluting balloons have been considered as the treatment of choice for in-stent restenosis. The study aims to determine the predictors of in-stent stenosis in patients undergoing percutaneous coronary intervention and to recommend measures to reduce the incidence of in-stent stenosis. This was a quantitative research study. It used the observational and descriptive retrospective approach focusing on patients who had in-stent restenosis after having percutaneous coronary intervention from June 2018 – February 2020. The study was conducted at a single practice called Dr Gafoor and Dr Soosiwala Inc. situated at the Ethekwini Heart centre, KwaZulu - Natal, Durban, South Africa. Permission to conduct the study was obtained from the hospital manager as well as the practice manager of Dr Gafoor and Dr Soosiwala Inc. The data was collected through patient’s files focusing on patients within the age group of 18 – 85 years. Statistical analysis The data was analysed using the SPSS Statistics 26.0 (Release August 2018) and Statgraphics centurion 15.1 (2006). The means standard deviation was analysed whereby a p value of less than 0.05 was considered statistically significant Results The collected data proved that the use of drug eluting stents improved the come backs of patients with in-stent restenosis, but this has not eradicated the problem. There has been a worldwide use of drug eluting stents being used in daily practice. Although management of drug eluting stent remains unclear, repeat percutaneous intervention remains the most frequently used treatment. Furthermore, baseline characteristics showed diabetic, hypertension and dyslipidemic patients had a higher risk of in-stent stenosis as compared to the other risk factors. (Diabetics 72%; hypertension 80% and dyslipidemia 78%). 4 out of 57 had acute and late stent thrombosis. 55% showed it was the left anterior descending artery that was affected most. Restenosis can be regarded as a complex disease, whereby, the pathophysiological mechanisms are not fully understood. The study showed restenosis was higher in diabetics, hypertension, dyslipidemia and the type of artery affected. However, not much difference was found in other patient risk factors such as age and smoking This study correlated with other research findings found in the literature. Nonetheless, longer-term work is required and further imaging of vessels should be used as well as studies to prove if this will help with eliminating further in-stent restenosis.