|Year : 2018 | Volume
| Issue : 2 | Page : 61-65
Six months outcome in patients undergoing percutaneous coronary intervention for true bifurcation lesions without side branch stenting
Rahul Subhashrao Chalwade, Ajay Sharma, Neeraj Pandit
Department of Cardiology, PGIMER and Ram Manohar Lohia Hospital, New Delhi, India
|Date of Web Publication||19-Jun-2018|
Rahul Subhashrao Chalwade
N1104, Ajnara Daffodil, Sector 137, Noida, Uttar Pradesh
Source of Support: None, Conflict of Interest: None
Context: Bifurcation lesions is one of the most challenging lesions in interventional cardiology. The optimal management is still a debate. Provisional stenting is preferred approach at present, yet with higher major adverse cardiovascular events (MACE) than other lesions.
Aims: The aim of this study is to evaluate outcome in patients with true coronary bifurcation lesion undergoing percutaneous coronary intervention with stenting of the main vessel without side branch (SB) intervention.
Design: This was prospective observational study.
Subjects and Methods: The study was conducted in patients with stable angina or unstable angina or non ST elevation MI (NSTEMI) attributable to a de novo true coronary bifurcation lesion involving the main vessel and SB. The main vessel diameter has to be ≥≥2.5 mm and the SB has to be ≥≥2.25 mm by visual estimate.
Statistical Analysis: Statistical analysis was performed using statistical software package SPSS v22.0.
Results: Fifty-three consecutive patients of true bifurcation lesions were studied. They underwent main vessel stenting and were followed up for 6 months. Mean age of 54.9 ± 8.4 was studied, 66% were male, 45.3% were single-vessel disease, left anterior descending (LAD)-diagonal was the most common (43.4%) target bifurcation lesion, most common medina class was 1,1,1 (43.4%). On 6 months follow-up, total MACE events were 12 (22.6%), most were contributed by Target lesion revascularization (TLR) 11 (20.75%). The MACE were significantly associated with diabetes and the extend of coronary artery disease..
Conclusions: Simple stenting strategy in true bifurcation lesions is associated with high MACE events. Further studies dedicated to true coronary bifurcation lesions are required to look for best strategy for these lesions.
Keywords: Bifurcation stenting, complex coronary intervention, interventional cardiology, true bifurcation lesion
|How to cite this article:|
Chalwade RS, Sharma A, Pandit N. Six months outcome in patients undergoing percutaneous coronary intervention for true bifurcation lesions without side branch stenting. Heart India 2018;6:61-5
|How to cite this URL:|
Chalwade RS, Sharma A, Pandit N. Six months outcome in patients undergoing percutaneous coronary intervention for true bifurcation lesions without side branch stenting. Heart India [serial online] 2018 [cited 2018 Jul 20];6:61-5. Available from: http://www.heartindia.net/text.asp?2018/6/2/61/234662
| Introduction|| |
Bifurcation comprises 15%–20% of all percutaneous coronary interventions (PCI). The optimal management is still a debate. Provisional stenting being preferred technique.
Two stent techniques with bare metal stents were associated with increased risk of short and long term adverse outcomes.,, Several randomized trials ,,,, with drug-eluting stents did not reveal different clinical outcomes when comparing provisional side branch (SB) stenting with complex strategies.
However, none of these studies were dedicated for true bifurcation. Hence whether these results can be applied to true bifurcation is doubtful.
Therefore, the present study was carried out to assess the outcome of simple stenting strategy in true bifurcation lesions.
| Subjects and Methods|| |
The study was prospective observational study.
Patients were of chronic stable angina symptomatic on optimal medical therapy, unstable angina, and non-ST elevation myocardial infarction (MI) patients attributable to de novo true coronary artery bifurcation lesion. Bifurcation lesions with main vessel diameter ≥2.5 mm and SB diameter ≥2.25 mm were included in the study. Key exclusion criteria were acute ST-elevation MI, left main bifurcation lesions, comorbid and terminally ill patients, glomerular filtration rate <60 ml/min/1.73 m 2, contraindication to angiography, allergy to any of the drugs used (aspirin, clopidogrel, sirolimus, everolimus, and paclitaxel).
Patients enrolled in the study underwent coronary angiography as per standard protocol. The severity of coronary stenosis was established on coronary angiography visually. Stenosis ≥50% was considered significant.
True bifurcation lesion was defined as a coronary artery narrowing occurring adjacent to and/or involving the origin of a significant SB. A significant SB was considered as a branch that we want to preserve in the global context of the patient.
The extent of bifurcation lesion was defined using Medina et al. classification.
Percutaneous coronary interventions procedure
Preprocedure adequate antiplatelet loading and anticoagulation was given.
The main treatment principles of the PCI procedure (provisional stenting) were as follows: wiring of both the MV and SB, predilatation of the stenosed areas of the MV at the discretion of the operator, followed by stenting of the MV and thus jailing of the SB wire. If there is thrombolysis in MI (TIMI) Grade 3 flow in the SB after MV stenting, the procedure was terminated even if a high-grade ostial SB stenosis is present. These patients were followed up in the study.
In case of SB flow less than TIMI Grade 3, the SB was treated by provisional SB stenting protocol with either kissing ballooning or with a stent. These patients were not included in the study. After main vessel stenting patient was managed medically as per departmental protocol.
Information on death and other major adverse cardiac events (MACEs) was obtained by clinical follow-up visit performed at 45 days, 3 and 6 months. If the patient did not come for clinical visit, they were contacted by phone for information on death and other MACE. Final follow up visit was performed at 6 months for primary end-point registration.
All patients were subjected to stress evaluation and patients with stress-induced ischemia were taken for coronary angiography. Patients with acute coronary syndrome during follow-up period directly were taken for coronary angiography. During coronary angiography, we looked for stent thrombosis, restenosis, and late lumen loss. Asymptomatic patients and stress evaluation negative patients were not subjected to follow-up coronary angiogram.
The clinical events were defined as follows:
- Death: the cause was confirmed by reviewing clinical records and deaths without clear non cardiac cause were considered as cardiac death
- MI: ST-segment elevation MI (<20 min lasting chest pain with >0.1 mV ST-segment elevation in at least two contiguous leads) or non–ST segment elevation MI (typical chest pain with documentation of transient >0.1 mV ST-segment depression or T-wave modifications in at least two contiguous leads) with any increase in serum cardiac enzymes above the 99th percentile of the upper reference limit
- Target vessel revascularization: repeat PCI or coronary surgery on the target vessel due to recurrent ischemia
- Stent thrombosis was defined according to the Academic Research Consortium criteria as follows: “definite” - angiography - or autopsy-confirmed stent thrombosis; “probable” - any unexplained death within first 30 days or any MI in the territory of the stent and in the absence of any other obvious cause; “possible” - any unexplained death after 30 days.
Statistical analysis was performed using statistical software package IBM SPSS v22.0 (IBM Corporation, United States). Data are represented as mean ± SD. Continuous variables were compared using t-test, and categorical variables were compared using Chi-squared test. Value of P < 0.05 was considered as statistically significant.
| Results|| |
A total 53 patients undergoing PCI for true bifurcation lesion from November 2014 to October 2015 were studied [Figure 1].
The mean age of study population was 54.9 years, and 66% were male. Out of 53 subjects, 16 patients (30.2%) had diabetes, 28 patients (52.8%) had hypertension, 21 patients (39.6%) had dyslipidemia, and 23 patients (43.4%) were smokers. Mean EF of patients was 58.6% [Table 1].
The most common reason for coronary angiogram was chronic stable angina (CSA) 28 (52.8%), most of the patients 24 (45.3%) had single vessel disease (SVD) and the most common target bifurcation lesion was LAD-diagonal in 23 (43.4%) [Table 1].
Out of 53 patients of true coronary bifurcation, 12 (22.6%) patients belonged to MEDINA (0, 1, 1) class, 18 (34%) patients belonged to MEDINA (1,0,1) class and 23 (43.4%) patients belonged to MEDINA (1, 1, 1) class [Table 1].
Out of 53 patients, 12 (22.6%) patients had MACE out of which 11 (20.75%) had target lesion revascularization for recurrent angina, 3 (5.7%) patients had MI, 1 (1.9%) patient had stent thrombosis and died and 31 (77.4%) had No MACE [Table 2].
| Discussion|| |
This 6 months follow-up study of simple bifurcation stenting strategy showed that a single stent strategy for an SB of ≥2.25 mm and the main vessel of ≥2.5 mm diameter has debatable outcome with previous studies. Previous studies have shown no clear advantage with more complex strategies.
In this study, mean age of patients was 54.9 years which was less by about 10 years from other similar trials, in which it ranged from 60 to 67 years. Compared to previous western studies subjects in the present study had a higher percentage of diabetes and smoking but a lower percentage of hypertension and dyslipidemia.
Most of the patients had SVD (45.3%) with the most common target bifurcation was LAD-diagonal (43.4%), these findings were matching with previous studies (BBC-ONE and Qing-Fei Lin et al.). MEDINA classification was used to classify patients in the present study, only true bifurcation lesions were taken for study. The most common lesion was MEDINA class 1, 1, 1 (43.4%) followed by 1,0,1 (34%) and 0, 1, 1 in (22.6%) patients. There are very few studies dedicated for the outcome of true bifurcation lesions, but in most of the studies, a maximum number of patients were with true bifurcation lesion. About 83% patients in BBC-ONE, 94% in Colombo study and 68% in the study by Ferenc et al. were true bifurcations.
In a study by Lin et al. also (only true bifurcation study), patients were divided according to MEDINA class, about 48% were MEDINA class 1, 1, 1 followed by 16% with MEDINA class 1,0,1 and 35% of patients were MEDINA class 0, 1, 1.
In comparison to BBC-ONE, present study differs in many ways. BBC ONE was not true bifurcation dedicated study as opposed to the present study. On follow-up, stress evaluation was not done so only around 15% of patients underwent repeat coronary angiogram, but in the present study, all patients on follow-up underwent stress evaluation, and percentage of patients with repeat coronary angiogram was higher (38%). Furthermore, the number of patients with diabetes was higher in the present study. Hence, these may be the reasons for higher target lesion revascularizations in the present study.
MACE in the present study was higher than NORDIC study  and study by Ferenc et al. with MACE in 15.8% and 12.9% of patients in simple strategy [Table 3]. However these studies were not dedicated to true bifurcation lesions.
The CACTUS study  compared crush technique with provisional stenting in true bifurcation. In this study, there was no significant difference between two strategies (15.8% vs. 15%) [Table 3]. However in that study crossover the rate of subjects in the provisional arm to two-stent strategy was high and up to one-third patients underwent provisional T stenting due to decreased TIMI flow. Hence, it may lead to underestimation of MACE in single stent strategy group.
The present study was similar to study conducted by Lin et al. in many aspects. Both were dedicated to true bifurcation lesions. The incidence of MACE was significantly higher in patients with simple strategy as compared to routine double stent strategy. The TLR was significantly higher in simple strategy (31.4% vs. 7.7%). This result was comparable to present study where simple strategy had TLR incidence of 20.75%, and MACE was 22.6% [Table 3].
Hence, these two true bifurcation studies showed results contradictory to previous reports; further large randomized studies may answer this dilemma of adopting single or double stent strategy for true coronary bifurcation lesions.
In the present study, we tried to correlate MACE with various angiographic characteristics to predict the outcome. Such correlation of MACE with different angiographic characteristics was not done in these previous studies. We found that patients with baseline triple vessel disease had a significantly higher incidence of MACE within 6 months. This can be explained by the fact that patients with TVD already tend diffuse and rapid disease progression, and hence, they are prone to higher MACE events.
As with other factors we studied to predict outcome in different coronary arteries. We found that the incidence of MACE events is not affected by the vessel involved.
The outcome is also not influenced by the medina class of lesion. There was no significant difference between all the three medina classes of lesions. This may be because only true bifurcation lesions were included in this study as opposed to previous studies where all bifurcation lesions were included. Hence, when true bifurcation lesions are considered, medina classification is not sufficient to predict the outcome. We should look for other factors of bifurcation lesion for outcome.
In this study, we also tried to correlate outcome of patients with different patient-related risk factors. We found out that the incidence of MACE was significantly higher in patients with diabetes as compared to nondiabetics (P = 0.029). Other risk factors such as age, sex, hypertension, smoking, and dyslipidemia had no significant correlation with outcome.
Large randomized studies are required, dedicated to true bifurcation lesions to decide whether primary double stent strategy is better as compared to single stent strategy in patients of true bifurcation lesions.
Limitations of study
The principle limitations of the present study were subjects were not compared with double stent strategy group. A number of patients were limited. Other characteristics of bifurcation were not considered as bifurcation angle, calcification, and thrombus burden. Angiographic follow-up was not done in all patients.
| Conclusions|| |
In the present study, we concluded that in true coronary bifurcation lesion when SB is significantly diseased (>50% stenosis) and suitable for stenting (≥2.25 mm), only main vessel stenting approach is associated with high MACE incidence.
The MACE incidence is significantly higher in patients with diabetes and underlying triple vessel disease undergoing PCI of bifurcation lesion.
In true bifurcation lesions outcome of stenting does not correlate with MEDINA class, so newer classification of true bifurcation lesions is required to predict the outcome.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3]