Coronary microvascular dysfunction in non infract related artery territory in patients presenting with acute myocardial infarction

Prayank Jain
2015 Indian Heart Journal  
Introduction and aims: Despite major advances in coronary stent technology, stent thrombosis (ST) remains a significant complication of percutaneous coronary intervention (PCI) with a high rate of MI and death, with multi-factorial underlying mechanisms. We sought to study clinical and angiographic profile of patients presenting with definite ST to our Institute. Methods: In this retrospective study, demographic and clinical data were collected for patients presenting with definite ST to our
more » ... finite ST to our Institute over the past decade, and angiographic images of same were reviewed. LV systolic and diastolic function was studied by 2D echocardiography and intracoronary thrombus was defined by angiography and graded as per standard systems. Details of PCI done were also collected. Results: A total of 53 patients (M = 34, F = 21) presented with definite ST. Of the ST cases, 35.9% (n = 19) were acute (within 24 h, 11 were acute STEMI within 24 h), 56.6% (n = 30) sub-acute (24 h-1 month), and 2 cases (3.7%), each classified as late (1-12 months) and very late (>1 year) after the initial PCI.10 patients died either before treatment could be instituted (possible in 3, probable in 2) or during PCI for ST (n = 5). Mean age of presentation was 49 years (range 34-72 years) and duration of occurrence of ST ranged from "on table" immediately following stent deployment in 4 patients, to very late in 2 (mean = 34.5 days, median 207 days). Mean LVEF in ST group was 35.5 AE 5.5%. The stent that had been implanted were: BMS in 25 patients, SES in 17,and PES in 11 patients. The ST group had more smokers (n = 32, 60.3%), more diabetics (n = 24, 45.2%), had h/o recent STEMI, (n = 41, 77.4%) and 4 were loaded with clopidogrel after the angiogram for an ad-hoc angioplasty procedure. Among the patients with ST, nine had been given eptifibatide after PCI, of whom 4 developed ST despite the use of same. Acute ST during primary PCI occurred in 5 patients ("on-table") of whom 3 were in cardiogenic shock with mean LVEF $30% and subsequently died. As per artery involved LAD was most common (n = 37, 69.8% cases). In all cases but two, stent length was more than 18 mm. Of interest is that 5 ST patients had Hb <12 g% and could be qualified as "anemic" by WHO standards, though this value did not reach significance in comparison with non-anemics who developed ST. Using univariate analysis, factors that were significantly higher in the ST group were noncompliance to DAPT use and/or interruption of therapy in 8 patients for another procedure (10.4%), and PCI in stenting for acute STEMI (with higher thrombus burden) in 11, with severe LV dysfunction. Most stents deployed in ST population measure >18 mm length (min = 10 mm, max = 33 mm). Presence of cardiogenic shock in patients undergoing PCI was significantly associated with higher incidence of ST and mortality. Anemic patients (even without requirement of blood transfusion) and patients loaded ad-hoc for angioplasty showed a trend towards higher ST. In terms of DAPT, 47 of the patients were on clopidogrel and 7 on prasugrel. Use of first-generation drug eluting stents v/s BMS or thrombus aspiration was not associated with lower grades of development of ST especially in acute setting. Interesting cases included a 44 year-old male with first presentation as ST and then
doi:10.1016/j.ihj.2015.10.085 fatcat:vhl2tcq3gza7dol2x6a2z7ddgu