Person:

Braunwald, Eugene

Aims: In the TRITON-TIMI 38 trial, greater platelet inhibition with prasugrel reduced the first occurrence of the primary endpoint (cardiovascular death, MI, or stroke) compared with clopidogrel in patients with an acute coronary syndrome (ACS) undergoing planned percutaneous coronary intervention. We hypothesized that prasugrel would reduce not only first events but also recurrent primary endpoint events and therefore total events compared with clopidogrel. Methods and results: Poisson regression analysis was performed to compare the number of occurrences of the primary endpoint between prasugrel and clopidogrel in TRITON-TIMI 38. Landmark analytic methods were used to evaluate the risk of a recurrent primary endpoint event following an initial non-fatal endpoint event. Among patients with an initial non-fatal event, second events were significantly reduced with prasugrel compared to clopidogrel (10.8 vs. 15.4%, HR 0.65, 95% CI 0.46–0.92; P = 0.016), as was CV death following the non-fatal event (3.7 vs. 7.1%, HR 0.46, 95% CI 0.25–0.82; P = 0.008). Overall there was a reduction of 195 total primary efficacy events with prasugrel vs. clopidogrel (rate ratio 0.79, 95% CI 0.71–0.87; P < 0.001). Recurrent bleeding events occurred infrequently (TIMI major non-CABG bleeds: four with prasugrel and two with clopidogrel). Study drug discontinuation was frequent following the initial major bleeding event (42% of patients discontinued study drug). Conclusion: While standard statistical analytic techniques for clinical trials censor patients who experience a component of the primary composite endpoint, total cardiovascular events remain important to both patients and clinicians. Prasugrel, a more potent anti-platelet agent, reduced both first and subsequent cardiovascular events compared with clopidogrel in patients with ACS.

A noninvasive technique for evaluating the extent of myocardial ischemic injury after experimental coronary artery occlusion was devised and applied to study alterations in the extent of injury produced by hemodynamic and pharmacologic interventions. The technique was then extended to the assessment of myocardial ischemic injury in patients with acute myocardial infarction. In 7 closed chest dogs, electrocardiograms were recorded from 15 sites on the chest wall before and after intermittent occlusions of the left anterior descending coronary artery. There was no S-T segment elevation before the occlusion; 15 minutes after occlusion the sum of S-T segment elevations (ΣS-T) averaged 15.0 ± 3.0 mm (SEM, 1 mm deflection = 0.1 mv), and an average of 4.2 ± 0.6 sites exhibited elevations exceeding 0.1 mv (NS-T). Occlusions occurring during administration of isoproterenol (0.25 μg/kg per min) increased ΣS-T to 51.0 ± 9.0 mm and NS-T to 10.6 ± 0.9, whereas occlusions occurring after administration of propranolol (1 mg/kg) decreased ΣS-T to 3.0 ± 1.5 mm and NS-T to 0.2 ± 0.2. In 8 dogs the extent of ischemic injury, manifested by S-T segment changes, was decreased by propranolol and norepinephrine and increased by hemorrhagic hypotension and isoproterenol, applied up to 6 hours after occlusion. Reproducible S-T segment maps, using 35 surface electrodes, were obtained in 19 patients with acute myocardial infarction. In 15 patients studied serially, ΣS-T decreased from 54.25 ± 7.00 to 38.50 ± 6.30 mm and NS-T from 18.7 ± 2.5 to 12.3 ± 2.8, respectively, during a 24 hour period. However, in 3 patients in whom ventricular fibrillation, arterial hypotension and further ischemic pain occurred, ΣS-T and NS-T increased whereas in another patient propranolol decreased ΣS-T and NS-T. Thus, precordial mapping, both in dogs and patients, shows changes parallel to those measured by the epicardial technique and should provide a useful clinical tool for determining acute changes in the extent of ischemic injury.

Since isoproterenol, tachycardia induced by atrial pacing, propranolol and Hyaluronidase alter the extent and severity of cardiac damage after coronary occlusion, their effects on the function of the severely ischemic heart were studied. In 40 dogs, blood from the femoral artery perfused the cannulated left coronary artery with flow controlled by a roller pump. Total left coronary blood flow was reduced progressively every 3 minutes from a control value of 84.2 ml/min per 100 g of left ventricular myocardium until mean left atrial pressure exceeded 20 mm Hg. In control runs, coronary blood flow decreased by 49 percent; with infusion of isoproterenol (0.08 μg/kg per min) coronary blood flow was reduced by only 24 percent (no. = 12, P < 0.01); after pretreatment with propranolol (1 mg/kg) coronary blood flow could be reduced by 55 percent (no. = 8, P < 0.05); and after pretreatment with Hyaluronidase (2,000 National Formulary units/kg) coronary blood flow could be reduced by 65 percent (no. = 6, P < 0.01) until left atrial pressure increased to 20 mm Hg. With coronary blood flow at 67 ml/min per 100 g, that is, at 75 percent of control value, left atrial pressure averaged 4.9 mm Hg at a heart rate of 120 beats/min and increased to 12.7 mm Hg (no. = 9, P < 0.01) at a heart rate of 165 beats/min. Thus, contrary to the effects of isoproterenol and tachycardia in the normal and failing nonischemic heart, these interventions depress left ventricular function in the severely ischemic heart, whereas propranolol and Hyaluronidase improve this function. The effects of these interventions on ventricular function parallel those produced by these same interventions on the extent and severity of myocardial injury in the presence of coronary occlusion.

Background Using a transcriptional profiling approach, we recently identified myeloid-related protein 8/14 (MRP-8/14) to be expressed by platelets during acute myocardial infarction (MI). Elevated concentrations of MRP-8/14 are associated with a higher risk for future cardiovascular events in apparently healthy individuals but have not been assessed with respect to prognosis in patients with acute coronary syndrome. Methods We performed a nested case-control study (n = 237 case-control pairs) among patients enrolled in the Pravastatin or Atorvastatin Evaluation and Infection Theraphy: Thrombolysis in Myocardial Infarction 22 (PROVE IT-TIMI 22) trial (mean follow-up 24 months) to investigate the risk of cardiovascular death or MI associated with MRP-8/14 measured at 30 days after an acute coronary syndrome. Results Patients with cardiovascular death or MI after 30 days (cases) had higher median [25th, 75th percentile] MRP-8/14 levels than patients who remained free of recurrent events (5.6 [2.8, 13.5] mg/L vs 4.0 [1.9, 10.1] mg/L, P = .020). The risk of a recurrent cardiovascular event increased with each increasing quartile of MRP-8/14 ( P-trend = 0.007) such that patients with the highest levels had a 2.0-fold increased odds (95% CI 1.1-3.6, P = .029) of a recurrent event after adjusting for standard risk indicators, randomized treatment, and C-reactive protein. Patients with elevated levels of MRP-8/14 and high-sensitivity C-reactive protein showed significantly increased risk of cardiovascular death or MI compared with patients with the lowest levels of both markers (adjusted odds ratio 2.1, 95% CI 1.2-3.8). Conclusions Myeloid-related protein 8/14 may be a useful biomarker of platelet and inflammatory disease activity in atherothrombosis and may serve as a novel target for therapeutic intervention.

The influence of the administration of pharmacologic doses of hydrocortisone on the extent and severity of acute myocardial ischemic injury and on subsequent necrosis after acute coronary occlusion was investigated in 28 dogs. In order to study acute myocardial injury, repeated epicardial electrocardiograms were recorded from 10 to 15 sites on the anterior surface of the left ventricle. Average ST segment elevation (ST) and the number of sites in which ST segment elevation exceeded 2 mV (NST), indices of the magnitude and extent of myocardial injury, respectively, were analyzed at 30 and 60 min after coronary occlusion. In the control group ST and NST did not change significantly in this time interval while in the treated group, which received 50 mg/kg hydrocortisone just after the 30 min recording, ST fell from 3.5+/-0.8 to 1.1+/-0.4 mV (P 2 mV) in the control group showed histologic changes compatible with early myocardial infarction in 96% of specimens, while this occurred only in 61% and 63% of specimens, respectively, in the treated groups, showing that over one third of the sites were protected from undergoing necrosis due to the intervening hydrocortisone treatment. Thus pharmacological doses of hydrocortisone prevent myocardial cells from progressing to ischemic necrosis even when administration is initiated 6 h after coronary occlusion.

Background: We studied the concomitant use of single antiplatelet therapy (SAPT) on the efficacy and safety of the anti‐Xa agent edoxaban in patients with atrial fibrillation (AF). Methods and Results: ENGAGE AF‐TIMI 48 was a randomized trial that compared 2 dose regimens of edoxaban with warfarin. We studied both the approved high‐dose edoxaban regimen (HDER; 60 mg daily reduced by one half in patients with anticipated increased drug exposure), as well as a lower‐dose edoxaban regimen (LDER; 30 mg daily, also reduced by one half in patients with anticipated increased drug regimen). SAPT (aspirin in 92.5%) was administered at the discretion of the treating physician. Cox proportional hazard regressions stratified by SAPT at 3 months with treatment as a covariate were performed. The 4912 patients who received SAPT were more frequently male, with histories of coronary artery disease and diabetes, and had higher CHADS 2Vasc and HAS BLED scores than did the 14 977 patients not receiving SAPT. When compared to patients not receiving SAPT, those receiving SAPT had a higher incidence of major bleeding; (adjusted hazard ratio [HR adj]=1.46; 95% CI, 1.27–1.67, P<0.001). SAPT did not alter the relative efficacy of edoxaban compared to warfarin in preventing stroke or systemic embolic events (SEEs): edoxaban versus warfarin without SAPT, hazard ratio (HR adj for HDER)=0.94; (95% CI: 0.77–1.15) with SAPT, HR adj=0.70 (95% CI: 0.50–0.98), P interaction (P int)=0.14. (HR adj for LDER versus warfarin without SAPT=1.19 (95% CI 0.99–1.43) With SAPT, 1.03 (95% CI, 0.76–1.39) P int=0.42. Major bleeding was lower with edoxaban than warfarin both without SAPT, HR adj for HDER=0.80 (95% CI, 0.68–0.95), and with SAPT, HR adj=0.82 (95% CI, 0.65–1.03; P int=0.91). For LDER without SAPT (HR adj=0.56 [95% CI 0.46–0.67]) and with SAPT (HR adj=0.51 [95% CI 0.39–0.66]). Conclusions: Patients with AF who were selected by their physicians to receive SAPT in addition to an anticoagulant had a similar risk of stroke/SEE and higher rates of bleeding than those not receiving SAPT. Edoxaban exhibited similar relative efficacy and reduced bleeding compared to warfarin, with or without concomitant SAPT. Clinical Trial Registration URL: http://www.clinicaltrials.gov/. Unique identifier: NCT00781391.

Background: Vorapaxar is a protease‐activated receptor‐1 antagonist approved by the U.S. Food and Drug Administration (FDA) for the reduction of thrombotic cardiovascular (CV) events in patients with a history of myocardial infarction (MI) and peripheral artery disease (PAD), without a previous stroke or transient ischemic attack (TIA). Methods and Results: We examined the efficacy and safety of vorapaxar in the intended use population, considering 20 170 patients randomized in the multinational, double‐blinded, placebo‐controlled TRA 2°P‐TIMI 50 trial. Of these, 16 897 qualified with a history of MI in the prior 2 weeks to 1 year and 3273 with PAD. At baseline 97% of the patients were treated with aspirin, 71% with a thienopyridine, and 93% a statin. At 3 years, the endpoint of CV death, MI, or stroke was significantly reduced with vorapaxar compared with placebo (7.9% versus 9.5%, HR, 0.80; 95% CI 0.73 to 0.89; P<0.001). Vorapaxar also significantly reduced the composite of CV death, MI, stroke, and urgent coronary revascularization (10.1% versus 11.8%, HR, 0.83; 95% CI 0.76 to 0.90; P<0.001), as well as the rate of CV death or MI (P<0.001). The safety endpoint of GUSTO moderate or severe bleeding, was increased in the vorapaxar group (3.7 versus 2.4, HR, 1.55; 95% CI 1.30 to 1.86, P<0.001). Intracranial bleeding (ICH) was 0.6% versus 0.4%, P=0.10 with vorapaxar versus placebo, with fatal bleeding 0.2% versus 0.2%; P=0.70. Conclusions: In patients with prior MI or PAD who have not had a previous stroke or TIA, vorapaxar added to standard therapy is effective for long‐term secondary prevention of thrombotic CV events, while increasing moderate or severe bleeding. Clinical Trial Registration URL: clinicaltrials.gov Unique Identifier: NCT00526474.

Background: Our dual aims were as follows: (1) to classify new or recurrent myocardial infarctions (MI) in patients with stable atherosclerosis using the Universal Definition of MI classification system; and (2) to characterize the effects of vorapaxar, a first‐in‐class platelet protease‐activated receptor ‐1 antagonist, on new or recurrent MI. Methods and Results: We analyzed data from TRA 2°P‐TIMI 50, a multinational, randomized, double‐blind, placebo‐controlled trial of vorapaxar. This analysis included 20 770 patients with previous MI or peripheral arterial disease without a history of transient ischemic attack or stroke. Each new or recurrent MI after randomization that met the trial end point definition was further categorized according to the European Society of Cardiology, American College of Cardiology, American Heart Association, World Heart Federation Universal Definition classification of type and size. Of 1095 incident MIs, 77% were spontaneous (Type 1), with a smaller number (9.8%) of secondary MIs (Type 2). Vorapaxar reduced Type 1 MI (hazard ratio [HR] 0.84, CI 0.73–0.98, P=0.024), with a similar pattern for Type 2 MI (HR 0.74, CI 0.49–1.10, P=0.13). Notably, vorapaxar showed a consistent pattern of reduction across size of MIs, including MIs in the highest Universal MI size class (≥10× upper reference limit, HR 0.83, CI 0.70–0.98, P=0.025). As such, there was a significant reduction in larger, spontaneous MIs (Type 1, ≥10× upper reference limit, HR 0.81, CI 0.67–0.99, P=0.036), and a consistent pattern with respect to fatal MI (HR 0.66, CI 0.39–1.11, P=0.12). Conclusions: Among stable patients with established atherosclerosis, the most common type of incident MI is spontaneous MI, and the reduction in MI with vorapaxar was consistent across MIs of varying type and size, including spontaneous infarctions ≥10× upper reference limit. Clinical Trial Registration URL: https://www.clinicaltrials.gov. Unique identifier: NCT00526474.

OBJECTIVES: To determine whether data on proteinuria are useful for refining estimates of risk based on kidney function alone, and whether the results of kidney function tests can be a useful adjunct to data on proteinuria. DESIGN: Analysis of data from a randomised trial. Impaired kidney function was defined as low glomerular filtration rate (< 60 ml/min/1.73 m2) and proteinuria (> or = 1+ protein) on dipstick urinalysis. SETTING: Study of cholesterol and recurrent events: a randomised trial of pravastatin 40 mg daily versus placebo. PARTICIPANTS: 4098 men and women with previous myocardial infarction. MAIN OUTCOME MEASURES: All cause mortality and cardiovascular events. RESULTS: 371 participants died in nearly 60 months of follow-up. Compared with participants without proteinuria or impaired kidney function, patients with both characteristics were at high risk (hazard ratio 2.39, 95% confidence interval 1.72 to 3.30), and those with only proteinuria or only impaired kidney function were at intermediate risk (1.69, 1.32 to 2.16; 1.41, 1.12 to 1.79, respectively) of dying from any cause. The results were similar for cardiovascular outcomes, including new cases of heart failure, stroke, and coronary death or non-fatal myocardial infarction. A graded increase in the risk of all cause mortality was seen for severity of renal impairment and degree of proteinuria by dipstick. CONCLUSIONS: The presence or absence of proteinuria on dipstick urinalysis may be used to refine estimates of risk based on kidney function alone.

Background: Elderly patients with atrial fibrillation are at higher risk of both ischemic and bleeding events compared to younger patients. In a prespecified analysis from the ENGAGE AF‐TIMI 48 trial, we evaluate clinical outcomes with edoxaban versus warfarin according to age. Methods and Results: Twenty‐one thousand one‐hundred and five patients enrolled in the ENGAGE AF‐TIMI 48 trial were stratified into 3 prespecified age groups: <65 (n=5497), 65 to 74 (n=7134), and ≥75 (n=8474) years. Older patients were more likely to be female, with lower body weight and reduced creatinine clearance, leading to higher rates of edoxaban dose reduction (10%, 18%, and 41% for the 3 age groups, P<0.001). Stroke or systemic embolic event (1.1%, 1.8%, and 2.3%) and major bleeding (1.8%, 3.3%, and 4.8%) rates with warfarin increased across age groups (P trend<0.001 for both). There were no interactions between age group and randomized treatment in the primary efficacy and safety outcomes. In the elderly (≥75 years), the rates of stroke/systemic embolic event were similar with edoxaban versus warfarin (hazard ratio 0.83 [0.66–1.04]), while major bleeding was significantly reduced with edoxaban (hazard ratio 0.83 [0.70–0.99]). The absolute risk difference in major bleeding (−82 events/10 000 pt‐yrs) and in intracranial hemorrhage (−73 events/10 000 pt‐yrs) both favored edoxaban over warfarin in older patients. Conclusions: Age has a greater influence on major bleeding than thromboembolic risk in patients with atrial fibrillation. Given the higher rates of bleeding and death with increasing age, treatment of elderly patients with edoxaban provides an even greater absolute reduction in safety events over warfarin, compared to treatment with edoxaban versus warfarin in younger patients. Clinical Trial Registration URL: https://www.clinicaltrials.gov/. Unique identifier: NCT00781391.