Reduction of stent thrombosis in patients with acute coronary syndromes treated with rivaroxaban in ATLAS-ACS 2 TIMI 51.

OBJECTIVES: The aim of this study was to determine if rivaroxaban is associated with a reduction in stent thrombosis among patients with acute coronary syndromes (ACS) in the ATLAS-ACS 2 TIMI 51 (Anti-Xa Therapy to Lower Cardiovascular Events in Addition to Standard Therapy in Subjects With Acute Coronary Syndrome-Thrombolysis in Myocardial Infarction 51) trial. BACKGROUND: Dual antiplatelet therapy (DAPT) has been the mainstay of efforts to prevent stent thrombosis. Because thrombin is a potent stimulant of platelet activation, we hypothesized that inhibition of thrombin generation via factor Xa inhibition may further reduce the risk of stent thrombosis. METHODS: The ATLAS-ACS 2 TIMI 51 study was a placebo-controlled trial that randomly assigned 15,526 patients with recent ACS to receive twice-daily doses of either 2.5 mg or 5 mg of rivaroxaban or placebo for a mean of 13 months and up to 31 months. RESULTS: Among patients who had a stent placed before or at the time of the index event, rivaroxaban significantly reduced independently adjudicated Academic Research Consortium definite and probable stent thrombosis in the pooled (1.9% vs. 1.5%; hazard ratio [HR]: 0.65; p = 0.017) and the 2.5 mg twice-daily (1.9% vs. 1.5%; HR: 0.61; p = 0.023) treatment groups when compared with placebo, with a trend toward a reduction in the 5 mg twice-daily treatment group (1.9% vs. 1.5%; HR: 0.70; p = 0.089). Among patients who received both aspirin and a thienopyridine (stratum 2), the benefit of rivaroxaban emerged during the period of active treatment with DAPT (HR: 0.68; 95% CI: 0.50 to 0.92, combined rivaroxaban group vs. placebo). Among stented patients who were treated with dual antiplatelet therapy, there was a mortality reduction among those treated with twice-daily rivaroxaban 2.5 mg (HR: 0.56; 95% CI: 0.35 to 0.89; p = 0.014). CONCLUSIONS: Among stented patients with ACS treated with DAPT, the administration of twice-daily rivaroxaban 2.5 mg was associated with a reduction in stent thrombosis and mortality. (An Efficacy and Safety Study for Rivaroxaban in Patients With Acute Coronary Syndrome; NCT00809965).

Four-year follow-up of TYPHOON (trial to assess the use of the CYPHer sirolimus-eluting coronary stent in acute myocardial infarction treated with BallOON angioplasty).

OBJECTIVES: The aim of this study was to assess the long-term safety and efficacy of the CYPHER (Cordis, Johnson and Johnson, Bridgewater, New Jersey) sirolimus-eluting coronary stent (SES) in percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI). BACKGROUND: Concern over the safety of drug-eluting stents implanted during PCI for STEMI remains, and long-term follow-up from randomized trials are necessary. TYPHOON (Trial to assess the use of the cYPHer sirolimus-eluting stent in acute myocardial infarction treated with ballOON angioplasty) randomized 712 patients with STEMI treated by primary PCI to receive either SES (n = 355) or bare-metal stents (BMS) (n = 357). The primary end point, target vessel failure at 1 year, was significantly lower in the SES group than in the BMS group (7.3% vs. 14.3%, p = 0.004) with no increase in adverse events. METHODS: A 4-year follow-up was performed. Complete data were available in 501 patients (70%), and the survival status is known in 580 patients (81%). RESULTS: Freedom from target lesion revascularization (TLR) at 4 years was significantly better in the SES group (92.4% vs. 85.1%; p = 0.002); there were no significant differences in freedom from cardiac death (97.6% and 95.9%; p = 0.37) or freedom from repeat myocardial infarction (94.8% and 95.6%; p = 0.85) between the SES and BMS groups. No difference in definite/probable stent thrombosis was noted at 4 years (SES: 4.4%, BMS: 4.8%, p = 0.83). In the 580 patients with known survival status at 4 years, the all-cause death rate was 5.8% in the SES and 7.0% in the BMS group (p = 0.61). CONCLUSIONS: In the 70% of patients with complete follow-up at 4 years, SES demonstrated sustained efficacy to reduce TLR with no difference in death, repeat myocardial infarction or stent thrombosis. (The Study to Assess AMI Treated With Balloon Angioplasty [TYPHOON]; NCT00232830).

B-type natriuretic peptide and the effect of ranolazine in patients with non-ST-segment elevation acute coronary syndromes: observations from the MERLIN-TIMI 36 (Metabolic Efficiency With Ranolazine for Less Ischemia in Non-ST Elevation Acute Coronary-Thrombolysis In Myocardial Infarction 36) trial.

OBJECTIVES: We designed a prospective evaluation of the interaction between B-type natriuretic peptide (BNP) and the effect of ranolazine in patients with acute coronary syndromes (ACS) as part of a randomized, blinded, placebo-controlled trial. BACKGROUND: Ranolazine is believed to exert anti-ischemic effects by reducing myocardial sodium and calcium overload and consequently ventricular wall stress. BNP increases in response to increased wall stress and is a strong risk indicator in ACS. METHODS: We measured plasma BNP in all available baseline samples (n = 4,543) among patients with non-ST-segment elevation ACS randomized to ranolazine or placebo in the MERLIN-TIMI 36 (Metabolic Efficiency With Ranolazine for Less Ischemia in Non-ST Elevation Acute Coronary-Thrombolysis In Myocardial Infarction 36) trial and followed them for a mean of 343 days. The primary end point was a composite of cardiovascular death, myocardial infarction, and recurrent ischemia. BNP elevation was defined as >80 pg/ml. RESULTS: Patients with elevated BNP (n = 1,935) were at significantly higher risk of the primary trial end point (26.4% vs. 20.4%, p < 0.0001), cardiovascular death (8.0% vs. 2.1%, p < 0.001), and myocardial infarction (10.6% vs. 5.8%, p < 0.001) at 1 year. In patients with BNP >80 pg/ml, ranolazine reduced the primary end point (hazard ratio [HR]: 0.79; 95% confidence interval [CI]: 0.66 to 0.94, p = 0.009). The effect of ranolazine in patients with BNP >80 pg/ml was directionally similar for recurrent ischemia (HR: 0.78; 95% CI: 0.62 to 0.98; p = 0.04) and cardiovascular death or myocardial infarction (HR: 0.83; 95% CI: 0.66 to 1.05, p = 0.12). There was no detectable effect in those with low BNP (p interaction value = 0.05). CONCLUSIONS: Our findings indicate that ranolazine may have enhanced efficacy in high-risk patients with ACS identified by increased BNP. The interaction of biomarkers of hemodynamic stress and the effects of ranolazine warrants additional investigation. (Metabolic Efficiency With Ranolazine for Less Ischemia in Non-ST Elevation Acute Coronary Syndromes; NCT00099788).

Three-dimensional echocardiography for quantitative analysis of left-ventricular aneurysm.

BACKGROUND: Quantitative analysis of left-ventricular (LV) aneurysms after myocardial infarction is prognostically relevant and assists in planning surgery. Three-dimensional (3D) echocardiography facilitates clear visualization of cardiac anatomy and accurate assessment of functional parameters. The aim of the present study was to determine the ability of 3D echocardiography to quantify LV aneurysms. METHODS: Ten patients with a known LV-aneurysm after myocardial infarction underwent 3D echocardiography and cardiac magnetic resonance (CMR) imaging at 1.5 Tesla within 3 days. For 3D echocardiography, a multiplanar transesophageal examination was performed with full LV coverage and the 3D dataset was analyzed offline. The LV-aneurysm was defined by a wall thickness <5 mm. The following quantitative parameters were determined: left ventricular end-diastolic and end-systolic volumes, LV myocardial mass (LV-mass) and mass of the LV-aneurysm. LV ejection fraction and percentage of aneurysm mass (%-aneurysm) were calculated. RESULTS: LV volumes and ejection fraction showed a strong correlation between 3D echocardiography and CMR (r = 0.94-0.97; P < 0.01). Importantly, the mass and percentage of mass of the LV-aneurysm demonstrated a high correlation as well (r = 0.94 and r = 0.86, respectively; P < 0.01). For all parameters, the calculated bias between both methods was found to be minimal (0.8-7.6%). CONCLUSIONS: Three-dimensional echocardiography proved to be a reliable tool for quantitative analysis of LV volumes, ejection fraction and aneurysm size in patients with prior myocardial infarction. In addition, 3D visualization of the complex cardiac anatomy in patients with LV-aneurysm may assist surgical procedure planning.

Complementary roles for biomarkers of biomechanical strain ST2 and N-terminal prohormone B-type natriuretic peptide in patients with ST-elevation myocardial infarction.

BACKGROUND: ST2 is a member of the interleukin-1 receptor family with a soluble form that is markedly upregulated on application of biomechanical strain to cardiac myocytes. Circulating ST2 levels are elevated in the setting of acute myocardial infarction, but the predictive value of ST2 independent of traditional clinical factors and of an established biomarker of biomechanical strain, N-terminal prohormone B-type natriuretic peptide (NT-proBNP), has not been established. METHODS AND RESULTS: We measured ST2 at baseline in 1239 patients with ST-elevation myocardial infarction from the CLopidogrel as Adjunctive ReperfusIon TherapY-Thrombolysis in Myocardial Infarction 28 (CLARITY-TIMI 28) trial. Per trial protocol, patients were to undergo coronary angiography after 2 to 8 days and were followed up for 30 days for clinical events. In contrast to NT-proBNP, ST2 levels were independent of clinical factors potentially related to chronic increased left ventricular wall stress, including age, hypertension, prior myocardial infarction, and prior heart failure; levels also were only modestly correlated with NT-proBNP (r=0.14). After adjustment for baseline characteristics and NT-proBNP levels, an ST2 level above the median was associated with a significantly greater risk of cardiovascular death or heart failure (third quartile: adjusted odds ratio, 1.42; 95% confidence interval, 0.68 to 3.57; fourth quartile: adjusted odds ratio, 3.57; 95% confidence interval, 1.87 to 6.81; P<0.0001 for trend). When both ST2 and NT-proBNP were added to a model containing traditional clinical predictors, the c statistic significantly improved from 0.82 (95% confidence interval, 0.77 to 0.87) to 0.86 (95% confidence interval, 0.81 to 0.90) (P=0.017). CONCLUSIONS: In ST-elevation myocardial infarction, high baseline ST2 levels are a significant predictor of cardiovascular death and heart failure independently of baseline characteristics and NT-proBNP, and the combination of ST2 and NT-proBNP significantly improves risk stratification. These data highlight the prognostic value of multiple, complementary biomarkers of biomechanical strain in ST-elevation myocardial infarction.