CMR Native T1 Mapping Allows Differentiation of Reversible Versus Irreversible Myocardial Damage in ST-Segment-Elevation Myocardial Infarction: An OxAMI Study (Oxford Acute Myocardial Infarction)

BACKGROUND

CMR T1 mapping is a quantitative imaging technique allowing the assessment of myocardial injury early after ST-segment-elevation myocardial infarction. We sought to investigate the ability of acute native T1 mapping to differentiate reversible and irreversible myocardial injury and its predictive value for left ventricular remodeling.

METHODS AND RESULTS

Sixty ST-segment-elevation myocardial infarction patients underwent acute and 6-month 3T CMR, including cine, T2-weighted (T2W) imaging, native shortened modified look-locker inversion recovery T1 mapping, rest first pass perfusion, and late gadolinium enhancement. T1 cutoff values for oedematous versus necrotic myocardium were identified as 1251 ms and 1400 ms, respectively, with prediction accuracy of 96.7% (95% confidence interval, 82.8% to 99.9%). Using the proposed threshold of 1400 ms, the volume of irreversibly damaged tissue was in good agreement with the 6-month late gadolinium enhancement volume (r=0.99) and correlated strongly with the log area under the curve troponin (r=0.80) and strongly with 6-month ejection fraction (r=-0.73). Acute T1 values were a strong predictor of 6-month wall thickening compared with late gadolinium enhancement.

CONCLUSIONS

Acute native shortened modified look-locker inversion recovery T1 mapping differentiates reversible and irreversible myocardial injury, and it is a strong predictor of left ventricular remodeling in ST-segment-elevation myocardial infarction. A single CMR acquisition of native T1 mapping could potentially represent a fast, safe, and accurate method for early stratification of acute patients in need of more aggressive treatment. Further confirmatory studies will be needed.

Rationale and design of the SYNTAX II trial evaluating the short to long-term outcomes of state-of-the-art percutaneous coronary revascularisation in patients with de novo three-vessel disease

AIMS

The applicability of the results of the SYNTAX trial comparing percutaneous coronary intervention (PCI) using first-generation drug-eluting stents (DES) with coronary artery bypass graft (CABG) surgery for the treatment of patients with complex coronary artery disease (CAD) has been challenged by recent major technical and procedural developments in coronary revascularisation. Functional assessment of coronary lesions has contributed to marked improvements in both safety and efficacy of DES implantation. In addition, the recent development of the SYNTAX score II, a clinical tool based on anatomical and clinical factors, allows individualised objective decision making regarding the optimal revascularisation modality in patients with complex CAD. The ongoing SYNTAX II trial is currently evaluating the effectiveness of the clinical and technological advances in the treatment of patients with complex (de novo three-vessel) CAD.

METHODS AND RESULTS

The SYNTAX II trial is a multicentre, all-comers, open-label, single-arm trial aiming to recruit 450 patients with de novo three-vessel CAD in approximately 25 European interventional cardiology centres. All patients will be selected and treated following the SYNTAX II strategy, which includes: a) establishing the appropriateness of revascularisation utilising the SYNTAX score II as a clinical tool to allow objective decision making by the Heart Team, b) ischaemia-driven revascularisation based on functional intracoronary assessment, c) implantation of the new-generation everolimus-eluting platinum chromium coronary stent with thin struts and abluminal bioabsorbable polymer coating to promote rapid vessel healing, d) intravascular ultrasound-guided DES implantation, and e) treatment at centres with expertise in CTO recanalisation. The primary endpoint is a composite of the major adverse cardiac and cerebral events (MACCE) rate at one-year follow-up compared to the historical PCI arm of the SYNTAX trial. An exploratory endpoint will be MACCE at five-year follow-up compared to the historical surgical arm of the SYNTAX trial.

CONCLUSIONS

The SYNTAX II trial will provide valuable information on outcomes of state-of-the-art PCI for the contemporary management of complex (de novo three-vessel) CAD. SYNTAX II will be of critical value in the design of future trials in this arena.

A risk scoring system to predict coronary stent thrombosis

OBJECTIVE

Stent thrombosis (ST) is a potentially life-threatening complication of percutaneous coronary intervention (PCI). We aimed to develop a scoring system to predict the risk of ST following PCI.

RESEARCH DESIGN AND METHODS

Odds ratios (ORs) for risk factors associated with ST were identified from a meta-analysis based on a systematic literature review, and through consensus expert opinion (Delphi-RAND method). The combined ORs were used to calculate risk scores for acute (within 24 hours), early (within 30 days) and late (31 days to 1 year) ST. Risk scores were validated against patient-level data from the TRITON-TIMI 38 study. Twenty risk factors were identified.

RESULTS

The most highly predictive factor for early and late ST was "incomplete duration of dual antiplatelet therapy". Derived total risk scores ranged from 0 to 22 for acute and early ST, and from 0 to 20 for late ST. Increasing scores were associated with an increasing risk of ST when applied to trial data. Model discrimination was 0.60 (p = .0028), 0.67 (p < .0001) and 0.66 (p < .0001) for acute, early and late ST respectively, indicating good discriminatory power for predicting ST. Key limitations included a lack of published data on acute ST, resulting in a risk score for this time point being based predominantly on expert opinion, and that it was not possible to map all risk factors to variables collected in the TRITON-TIMI 38 study.

CONCLUSION

Our weighted scoring system may help to stratify ST risk and individualize antiplatelet therapy in patients undergoing PCI.

Variation in emergency percutaneous coronary intervention in ventilated patients in the UK: Insights from a national database

AIMS

Pre-procedural ventilation is a marker of high risk in PCI patients. Causes include out-of-hospital cardiac arrest (OHCA) and cardiogenic shock. OHCA occurs in approximately 60,000 patients in the UK per annum. No consensus exists regarding the need/timing of coronary angiography ± revascularization without ST elevation. The aim was to describe the national variation in the rate of emergency PCI in ventilated patients.

METHODS AND RESULTS

Using the UK national database for PCI in 2013, we identified all procedures performed as 'emergency' or 'salvage' for whom ventilation had been initiated before the PCI. Of the 92,589 patients who underwent PCI, 1342 (5.5%) fulfilled those criteria. There was wide variation in practice. There was no demonstrable relationship between the number of emergency PCI patients with pre-procedure ventilation per annum and (i) total number of PPCIs in a unit (r=-0.186), and (ii) availability of 24h PCI, (iii) on-site surgical cover.

CONCLUSION

We demonstrated a wide variation in practice across the UK in rates of pre-procedural ventilation in emergency PCI. The majority of individuals will have suffered an OHCA. In the absence of a plausible explanation for this discrepant practice, it is possible that (a) some patients presenting with OHCA that may benefit from revascularization are being denied treatment and (b) procedures may be being undertaken that are futile. Further prospective data are needed to aid in production of guidelines aiming at standardized care in OHCA.

Everolimus-Eluting Stents or Bypass Surgery for Left Main Coronary Artery Disease

BACKGROUND

Patients with obstructive left main coronary artery disease are usually treated with coronary-artery bypass grafting (CABG). Randomized trials have suggested that drug-eluting stents may be an acceptable alternative to CABG in selected patients with left main coronary disease.

METHODS

We randomly assigned 1905 eligible patients with left main coronary artery disease of low or intermediate anatomical complexity to undergo either percutaneous coronary intervention (PCI) with fluoropolymer-based cobalt-chromium everolimus-eluting stents (PCI group, 948 patients) or CABG (CABG group, 957 patients). Anatomic complexity was assessed at the sites and defined by a Synergy between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery (SYNTAX) score of 32 or lower (the SYNTAX score reflects a comprehensive angiographic assessment of the coronary vasculature, with 0 as the lowest score and higher scores [no upper limit] indicating more complex coronary anatomy). The primary end point was the rate of a composite of death from any cause, stroke, or myocardial infarction at 3 years, and the trial was powered for noninferiority testing of the primary end point (noninferiority margin, 4.2 percentage points). Major secondary end points included the rate of a composite of death from any cause, stroke, or myocardial infarction at 30 days and the rate of a composite of death, stroke, myocardial infarction, or ischemia-driven revascularization at 3 years. Event rates were based on Kaplan-Meier estimates in time-to-first-event analyses.

RESULTS

At 3 years, a primary end-point event had occurred in 15.4% of the patients in the PCI group and in 14.7% of the patients in the CABG group (difference, 0.7 percentage points; upper 97.5% confidence limit, 4.0 percentage points; P=0.02 for noninferiority; hazard ratio, 1.00; 95% confidence interval, 0.79 to 1.26; P=0.98 for superiority). The secondary end-point event of death, stroke, or myocardial infarction at 30 days occurred in 4.9% of the patients in the PCI group and in 7.9% in the CABG group (P<0.001 for noninferiority, P=0.008 for superiority). The secondary end-point event of death, stroke, myocardial infarction, or ischemia-driven revascularization at 3 years occurred in 23.1% of the patients in the PCI group and in 19.1% in the CABG group (P=0.01 for noninferiority, P=0.10 for superiority).

CONCLUSIONS

In patients with left main coronary artery disease and low or intermediate SYNTAX scores by site assessment, PCI with everolimus-eluting stents was noninferior to CABG with respect to the rate of the composite end point of death, stroke, or myocardial infarction at 3 years. (Funded by Abbott Vascular; EXCEL ClinicalTrials.gov number, NCT01205776 .).

Percutaneous coronary angioplasty versus coronary artery bypass grafting in treatment of unprotected left main stenosis (NOBLE): a prospective, randomised, open-label, non-inferiority trial

BACKGROUND

Coronary artery bypass grafting (CABG) is the standard treatment for revascularisation in patients with left main coronary artery disease, but use of percutaneous coronary intervention (PCI) for this indication is increasing. We aimed to compare PCI and CABG for treatment of left main coronary artery disease.

METHODS

In this prospective, randomised, open-label, non-inferiority trial, patients with left main coronary artery disease were enrolled in 36 centres in northern Europe and randomised 1:1 to treatment with PCI or CABG. Eligible patients had stable angina pectoris, unstable angina pectoris, or non-ST-elevation myocardial infarction. Exclusion criteria were ST-elevation myocardial infarction within 24 h, being considered too high risk for CABG or PCI, or expected survival of less than 1 year. The primary endpoint was major adverse cardiac or cerebrovascular events (MACCE), a composite of all-cause mortality, non-procedural myocardial infarction, any repeat coronary revascularisation, and stroke. Non-inferiority of PCI to CABG required the lower end of the 95% CI not to exceed a hazard ratio (HR) of 1·35 after up to 5 years of follow-up. The intention-to-treat principle was used in the analysis if not specified otherwise. This trial is registered with ClinicalTrials.gov identifier, number NCT01496651.

FINDINGS

Between Dec 9, 2008, and Jan 21, 2015, 1201 patients were randomly assigned, 598 to PCI and 603 to CABG, and 592 in each group entered analysis by intention to treat. Kaplan-Meier 5 year estimates of MACCE were 29% for PCI (121 events) and 19% for CABG (81 events), HR 1·48 (95% CI 1·11-1·96), exceeding the limit for non-inferiority, and CABG was significantly better than PCI (p=0·0066). As-treated estimates were 28% versus 19% (1·55, 1·18-2·04, p=0·0015). Comparing PCI with CABG, 5 year estimates were 12% versus 9% (1·07, 0·67-1·72, p=0·77) for all-cause mortality, 7% versus 2% (2·88, 1·40-5·90, p=0·0040) for non-procedural myocardial infarction, 16% versus 10% (1·50, 1·04-2·17, p=0·032) for any revascularisation, and 5% versus 2% (2·25, 0·93-5·48, p=0·073) for stroke.

INTERPRETATION

The findings of this study suggest that CABG might be better than PCI for treatment of left main stem coronary artery disease.

FUNDING

Biosensors, Aarhus University Hospital, and participating sites.

European real world trans-catheter aortic valve implantation: systematic review and meta-analysis of European national registries

Objective

Transcatheter aortic valve implantation (TAVI) has been adopted rapidly in Europe. TAVI national registries can augment understanding of technologies and represent real-world experience, providing further clinical insights. We undertook a meta-analysis of published European national TAVI registries to assess current results following TAVI in Europe.

Methods

Electronic databases were searched. The review focused on the comparison of the following TAVI strategies: transfemoral (TF) and transapical (TA) SAPIEN and CoreValve implantation. Individual event rates for outcomes of interest were pooled using a mixed effect model.

Results

Seven European national TAVI registries (UK, Swiss, Belgium, Italy, Spain, France, Germany) were identified, including a total of 9786 patients who received TF-SAPIEN (n = 2885), TA-SAPIEN (n = 2252) and CoreValve (n = 4649) implantation. Pooled incidence of 30-day mortality was 0.08% [95% Confidence Interval (CI): 0.05–0.11], 0.12% [95% CI: 0.07–0.19] and 0.06% [95% CI: 0.03–0.11] for TF-SAPIEN, TA-SAPIEN and CoreValve respectively (test for subgroup difference P = 0.18); there was high heterogeneity across European countries. Pooled incidence of stroke was comparable among the TAVI strategies (test for subgroup difference P = 0.79); the incidence of post-procedural moderate paravalvular leak ≥ 2 (P = 0.9) was similar across groups. CoreValve implantation was associated with an increased risk of pacemaker implantation (0.22 [95% CI: 0.19–0.26]; test for subgroup difference P < 0.0001). The lowest 30-day mortality was associated with TAVI performed in Spain (b coefficient −4.3; P = 0.03), in Italy (b coefficient −2.1; P < 0.0001), in UK (b coefficient −1.95; P = 0.01) and in France (b coefficient −2.8; P = 0.03). The German registry has the highest mortality for every TAVI strategy amongst all other European registries and especially for the TA-SAPIEN group.

Conclusions

Transarterial TAVI approaches were associated with a low early mortality regardless of the type of device used. There was marked heterogeneity among European countries for early mortality.