Antiplatelet drug selection in PCI to vein grafts in patients with acute coronary syndrome and adverse clinical outcomes: Insights from the British Cardiovascular Intervention Society database

OBJECTIVE

This study aims to evaluate outcomes associated with different P2Y12 agents in Saphenous Vein graft (SVG) percutaneous coronary intervention (PCI).

BACKGROUND

SVG PCI is associated with greater risks of ischemic complications, compared with native coronary PCI. Outcomes associated with the use of potent P2Y12 blocking drugs, Prasugrel and Ticagrelor, in SVG PCI are unknown.

METHODS

Patients included in the study underwent SVG PCI in the United Kingdom between 2007 and 2014 for acute coronary syndrome and were grouped by P2Y12 antiplatelet use. In-hospital major adverse cardiac events, major bleeding and 30-day and 1-year mortality were examined. Multiple imputations with chained equations to impute missing data were used. Adjustment for baseline imbalances was performed using (1) multiple logistic regression (MLR) and (separately) (2) propensity score matching (PSM).

RESULTS

Data weres analyzed from 8,119 patients and most cases were treated with Clopidogrel (n = 7,401), followed by Ticagrelor (n = 497) and Prasugrel (n = 221). In both MLR and PSM models, there was no significant evidence to suggest that either Prasugrel or Ticagrelor was associated with significantly lower 30-day mortality compared with Clopidogrel. The odds ratios reported from the multivariable analysis were 1.22 (95% CI: 0.60-2.51) for Prasugrel vs. Clopidogrel and 0.48 (95% CI: 0.20-1.16) for Ticagrelor vs. Clopidogrel. No significant differences were seen for in-hospital ischemic or bleeding events.

CONCLUSIONS

Our real world national study provides no clear evidence to indicate that use of potent P2Y12 blockers in SVG PCI is associated with improved clinical outcomes.

Minimising radial injury: prevention is better than cure

Transradial (TR) coronary intervention is associated with fewer access-site-related bleeding complications and is independently associated with a lower risk of mortality following PCI compared to procedures undertaken through the femoral route. However, recent studies that have undertaken imaging of the radial artery through the use of IVUS and OCT, as well as histological studies, suggest that TR cardiac catheterisation is associated with significant injury to the radial artery wall resulting in significant endothelial cell dysfunction. The vascular endothelium plays a central role in the regulation of vascular tone, angiogenesis and vascular remodelling through the release of vasoactive mediators in response to a variety of stimuli. Hence, trauma to the vascular endothelium and subsequent changes in endothelial cell function may contribute to patterns of injury such as intimal hyperplasia and radial artery occlusion observed following TR cardiac catheterisation. Such injury patterns to the radial artery following TR procedures may limit the success and future utility of the TR approach. Minimisation of radial artery injury should be a key procedural component of procedures undertaken through the transradial approach.

Thrombus capture by withdrawal of an open filter device: a useful treatment for large non-occlusive coronary thrombus

AIMS

The aim of this study was to assess the safety and feasibility of manual removal of a non-occlusive coronary thrombus using an open filter device. Between April 2006 and December 2011, 1,102 patients were treated percutaneously for acute coronary syndrome at our institution. Of these, nine (1%) had a large "cannon-ball" non-occlusive intracoronary thrombus, which did not improve with standard thrombectomy aspiration catheters. In these patients, we describe a novel technique of thrombus removal using the ev3 Spider™ filter device. Four patients had LAD thrombus, three had RCA thrombus, one LCX thrombus and one SVG thrombus. The primary endpoint of substantial or complete thrombus removal, prevention of no-reflow/slow flow phenomenon and achievement of TIMI 3 flow post stenting was achieved in all cases. Coronary dissection occurred in one case where the lesion was heavily calcified. There were no other complications related to the device. This is the first case series describing the use of the ev3 Spider™ filter device for the removal of a large intracoronary thrombus refractory to conventional treatment. This was associated with a high procedural success rate and may reduce the risk of no-reflow in these cases.

Clinical significance of histological features of thrombi in patients with myocardial infarction

Background

Percutaneous Coronary Intervention (PCI) is the most common strategy for the treatment of Acute ST segment elevation Myocardial Infarction (STEMI), and thromboaspiration has been increasingly utilized for removal of occlusive thrombi.

Objectives

To analyze the influence of histopathological features of coronary thrombi in clinical outcomes of patients with STEMI, and the association of these variables with clinical, angiographic, and laboratory features and medications used in hospitalization.

Methods

Prospective cohort study. All patients were monitored during hospitalization and thirty days after the event. Aspirated thrombi were preserved in formalin and subsequently stained with hematoxylin-eosin and embedded in paraffin. Thrombi were classified as recent and old. The primary outcome was the occurrence of major cardiovascular events within thirty days.

Results

During the study period, 1,149 patients were evaluated with STEMI, and 331 patients underwent thrombi aspiration, leaving 199 patients available for analysis. It was identified recent thrombi in 116 patients (58%) and old thrombi in 83 patients (42%). Recent thrombi have greater infiltration of red blood cells than old thrombi (p = 0.02), but there were no statistically significant differences between other clinical, angiographic, laboratory, and histopathological features and medications in both group of patients. The rates of clinical outcomes were similar in both groups.

Conclusions

Recent thrombi were identified in 58% of patients with STEMI and it was observed an association with infiltration of red blood cells. There was no association between histopathological features of thrombi and clinical variables and cardiovascular outcomes.

Systematic review: comparative effectiveness of adjunctive devices in patients with ST-segment elevation myocardial infarction undergoing percutaneous coronary intervention of native vessels

BACKGROUND

During percutaneous coronary intervention (PCI), dislodgement of atherothrombotic material from coronary lesions can result in distal embolization, and may lead to increased major adverse cardiovascular events (MACE) and mortality. We sought to systematically review the comparative effectiveness of adjunctive devices to remove thrombi or protect against distal embolization in patients with ST-segment elevation myocardial infarction (STEMI) undergoing PCI of native vessels.

METHODS

We conducted a systematic literature search of Medline, the Cochrane Database, and Web of Science (January 1996-March 2011), http://www.clinicaltrials.gov, abstracts from major cardiology meetings, TCTMD, and CardioSource Plus. Two investigators independently screened citations and extracted data from randomized controlled trials (RCTs) that compared the use of adjunctive devices plus PCI to PCI alone, evaluated patients with STEMI, enrolled a population with 95% of target lesion(s) in native vessels, and reported data on at least one pre-specified outcome. Quality was graded as good, fair or poor and the strength of evidence was rated as high, moderate, low or insufficient. Disagreement was resolved through consensus.

RESULTS

37 trials met inclusion criteria. At the maximal duration of follow-up, catheter aspiration devices plus PCI significantly decreased the risk of MACE by 27% compared to PCI alone. Catheter aspiration devices also significantly increased the achievement of ST-segment resolution by 49%, myocardial blush grade of 3 (MBG-3) by 39%, and thrombolysis in myocardial infarction (TIMI) 3 flow by 8%, while reducing the risk of distal embolization by 44%, no reflow by 48% and coronary dissection by 70% versus standard PCI alone. In a majority of trials, the use of catheter aspiration devices increased procedural time upon qualitative assessment.Distal filter embolic protection devices significantly increased the risk of target revascularization by 39% although the use of mechanical thrombectomy or embolic protection devices did not significantly impact other final health outcomes. Distal balloon or any embolic protection device increased the achievement of MBG-3 by 61% and 20% and TIMI3 flow by 11% and 6% but did not significantly impact other intermediate outcomes versus control. Upon qualitative analysis, all device categories, with exception of catheter aspiration devices, appear to significantly prolong procedure time compared to PCI alone while none appear to significantly impact ejection fraction. Many of the final health outcome and adverse event evaluations were underpowered and the safety of devices overall is unclear due to insufficient amounts of data.

CONCLUSIONS

In patients with STEMI, for most devices, few RCTs evaluated final health outcomes over a long period of follow-up. Due to insufficient data, the safety of these devices is unclear.

Percutaneous coronary intervention of unprotected left main coronary artery disease as culprit lesion in patients with acute myocardial infarction

OBJECTIVES

This study sought to evaluate short- and long-term outcomes of patients undergoing emergency percutaneous coronary intervention (PCI) for acute myocardial infarction due to a culprit lesion in an unprotected left main coronary artery.

METHODS

In this retrospective, 2-center, international observational study, 5,261 patients were admitted between February 2005 and December 2008 with acute myocardial infarction and treated with PCI; of these, 1,277 were ST-segment elevation myocardial infarction and 3,984 non-ST-segment elevation myocardial infarction. We identified 48 patients among this cohort who underwent emergency PCI to an unprotected left main coronary artery culprit lesion.

RESULTS

Mean age was 70 ± 12.5 years, and 45% of the patients presented with ST-segment elevation myocardial infarction or new left bundle branch block. Cardiogenic shock was present in 45%, and distal left main coronary artery disease was present in 71% of patients. Angiographic procedural success was achieved in 92% of patients. Overall in-hospital mortality was 21%, due in all cases to refractory, multiorgan failure. Twenty-five percent experienced major adverse cardiac events, defined as death, myocardial infarction, stent thrombosis, and target vessel revascularization. In patients presenting in cardiogenic shock, in-hospital mortality was 32%. At 1-year follow-up, in-hospital survivors had a mortality rate of 10.5%, whereas 18.4% experienced subsequent major adverse cardiac events. Long-term prognosis was excellent in hospital survivors with a 1-year survival rate of 89.5%.

CONCLUSIONS

Patients with acute myocardial infarction and thrombosis of the unprotected left main coronary artery are a high-risk subgroup with a substantial mortality, particularly if they present in cardiogenic shock. We demonstrate that in these patients, PCI is a feasible treatment option associated with reasonably good outcomes. Long-term prognosis is excellent in hospital survivors with an 89.5% survival rate at 1 year.