Susan L Morrisson

Bio: Susan L Morrisson is an academic researcher. The author has an hindex of 1, co-authored 1 publications receiving 636 citations.

Intensive versus moderate lipid lowering with statins after acute coronary syndromes.

Abstract: background Lipid-lowering therapy with statins reduces the risk of cardiovascular events, but the optimal level of low-density lipoprotein (LDL) cholesterol is unclear. methods We enrolled 4162 patients who had been hospitalized for an acute coronary syndrome within the preceding 10 days and compared 40 mg of pravastatin daily (standard therapy) with 80 mg of atorvastatin daily (intensive therapy). The primary end point was a composite of death from any cause, myocardial infarction, documented unstable angina requiring rehospitalization, revascularization (performed at least 30 days after randomization), and stroke. The study was designed to establish the noninferiority of pravastatin as compared with atorvastatin with respect to the time to an end-point event. Follow-up lasted 18 to 36 months (mean, 24). results The median LDL cholesterol level achieved during treatment was 95 mg per deciliter (2.46 mmol per liter) in the standard-dose pravastatin group and 62 mg per deciliter (1.60 mmol per liter) in the high-dose atorvastatin group (P<0.001). Kaplan–Meier estimates of the rates of the primary end point at two years were 26.3 percent in the pravastatin group and 22.4 percent in the atorvastatin group, reflecting a 16 percent reduction in the hazard ratio in favor of atorvastatin (P=0.005; 95 percent confidence interval, 5 to 26 percent). The study did not meet the prespecified criterion for equivalence but did identify the superiority of the more intensive regimen. conclusions Among patients who have recently had an acute coronary syndrome, an intensive lipidlowering statin regimen provides greater protection against death or major cardiovascular events than does a standard regimen. These findings indicate that such patients benefit from early and continued lowering of LDL cholesterol to levels substantially below current target levels.

Effect of clopidogrel added to aspirin in patients with atrial fibrillation.

Abstract: Background Vitamin K antagonists reduce the risk of stroke in patients with atrial fibrillation but are considered unsuitable in many patients, who usually receive aspirin instead. We investigated the hypothesis that the addition of clopidogrel to aspirin would reduce the risk of vascular events in patients with atrial fibrillation. Methods A total of 7554 patients with atrial fibrillation who had an increased risk of stroke and for whom vitamin K–antagonist therapy was unsuitable were randomly assigned to receive clopidogrel (75 mg) or placebo, once daily, in addition to aspirin. The primary outcome was the composite of stroke, myocardial infarction, non–central nervous system systemic embolism, or death from vascular causes. Results At a median of 3.6 years of follow-up, major vascular events had occurred in 832 patients receiving clopidogrel (6.8% per year) and in 924 patients receiving placebo (7.6% per year) (relative risk with clopidogrel, 0.89; 95% confidence interval [CI], 0.81 to 0.98; P = 0.01). The difference was primarily due to a reduction in the rate of stroke with clopidogrel. Stroke occurred in 296 patients receiving clopidogrel (2.4% per year) and 408 patients receiving placebo (3.3% per year) (relative risk, 0.72; 95% CI, 0.62 to 0.83; P<0.001). Myocardial infarction occurred in 90 patients receiving clopidogrel (0.7% per year) and in 115 receiving placebo (0.9% per year) (relative risk, 0.78; 95% CI, 0.59 to 1.03; P = 0.08). Major bleeding occurred in 251 patients receiving clopidogrel (2.0% per year) and in 162 patients receiving placebo (1.3% per year) (relative risk, 1.57; 95% CI, 1.29 to 1.92; P<0.001). Conclusions In patients with atrial fibrillation for whom vitamin K–antagonist therapy was unsuitable, the addition of clopidogrel to aspirin reduced the risk of major vascular events, especially stroke, and increased the risk of major hemorrhage. (ClinicalTrials.gov number, NCT00249873.)

Standard- vs high-dose clopidogrel based on platelet function testing after percutaneous coronary intervention: the GRAVITAS randomized trial.

Abstract: Context High platelet reactivity while receiving clopidogrel has been linked to cardiovascular events after percutaneous coronary intervention (PCI), but a treatment strategy for this issue is not well defined. Objective To evaluate the effect of high-dose compared with standard-dose clopidogrel in patients with high on-treatment platelet reactivity after PCI. Design, Setting, and Patients Randomized, double-blind, active-control trial (Gauging Responsiveness with A VerifyNow assay—Impact on Thrombosis And Safety [GRAVITAS]) of 2214 patients with high on-treatment reactivity 12 to 24 hours after PCI with drug-eluting stents at 83 centers in North America between July 2008 and April 2010. Interventions High-dose clopidogrel (600-mg initial dose, 150 mg daily thereafter) or standard-dose clopidogrel (no additional loading dose, 75 mg daily) for 6 months. Main Outcome Measures The primary end point was the 6-month incidence of death from cardiovascular causes, nonfatal myocardial infarction, or stent thrombosis. The key safety end point was severe or moderate bleeding according to the Global Utilization of Streptokinase and t-PA for Occluded Coronary Arteries (GUSTO) definition. A key pharmacodynamic end point was the rate of persistently high on-treatment reactivity at 30 days. Results At 6 months, the primary end point had occurred in 25 of 1109 patients (2.3%) receiving high-dose clopidogrel compared with 25 of 1105 patients (2.3%) receiving standard-dose clopidogrel (hazard ratio [HR], 1.01; 95% confidence interval [CI], 0.58-1.76; P = .97). Severe or moderate bleeding was not increased with the high-dose regimen (15 [1.4%] vs 25 [2.3%], HR, 0.59; 95% CI, 0.31-1.11; P = .10). Compared with standard-dose clopidogrel, high-dose clopidogrel provided a 22% (95% CI, 18%-26%) absolute reduction in the rate of high on-treatment reactivity at 30 days (62%; 95% CI, 59%-65% vs 40%; 95% CI, 37%-43%; P Conclusions Among patients with high on-treatment reactivity after PCI with drug-eluting stents, the use of high-dose clopidogrel compared with standard-dose clopidogrel did not reduce the incidence of death from cardiovascular causes, nonfatal myocardial infarction, or stent thrombosis. Trial Registration clinicaltrials.gov Identifier: NCT00645918

Comparison of fondaparinux and enoxaparin in acute coronary syndromes.

Abstract: BACKGROUND: The combined use of anticoagulants, antiplatelet agents, and invasive coronary procedures reduces ischemic coronary events but also increases bleeding in patients with acute coronary syndromes. We therefore assessed whether fondaparinux would preserve the anti-ischemic benefits of enoxaparin while reducing bleeding. METHODS: We randomly assigned 20,078 patients with acute coronary syndromes to receive either fondaparinux (2.5 mg daily) or enoxaparin (1 mg per kilogram of body weight twice daily) for a mean of six days and evaluated death, myocardial infarction, or refractory ischemia at nine days (the primary outcome); major bleeding; and their combination. Patients were followed for up to six months. RESULTS: The number of patients with primary-outcome events was similar in the two groups (579 with fondaparinux [5.8 percent] vs. 573 with enoxaparin [5.7 percent]; hazard ratio in the fondaparinux group, 1.01; 95 percent confidence interval, 0.90 to 1.13), satisfying the noninferiority criteria. The number of events meeting this combined outcome showed a nonsignificant trend toward a lower value in the fondaparinux group at 30 days (805 vs. 864, P=0.13) and at the end of the study (1222 vs. 1308, P=0.06). The rate of major bleeding at nine days was markedly lower with fondaparinux than with enoxaparin (217 events [2.2 percent] vs. 412 events [4.1 percent]; hazard ratio, 0.52; P<0.001). The composite of the primary outcome and major bleeding at nine days favored fondaparinux (737 events [7.3 percent] vs. 905 events [9.0 percent]; hazard ratio, 0.81; P<0.001). Fondaparinux was associated with a significantly reduced number of deaths at 30 days (295 vs. 352, P=0.02) and at 180 days (574 vs. 638, P=0.05). CONCLUSIONS: Fondaparinux is similar to enoxaparin in reducing the risk of ischemic events at nine days, but it substantially reduces major bleeding and improves long term mortality and morbidity. (ClinicalTrials.gov number, NCT00139815.).

Registries for Evaluating Patient Outcomes: A User's Guide

Abstract: This user’s guide is intended to support the design, implementation, analysis, interpretation, and quality evaluation of registries created to increase understanding of patient outcomes. For the purposes of this guide, a patient registry is an organized system that uses observational study methods to collect uniform data (clinical and other) to evaluate specified outcomes for a population defined by a particular disease, condition, or exposure, and that serves one or more predetermined scientific, clinical, or policy purposes. A registry database is a file (or files) derived from the registry. Although registries can serve many purposes, this guide focuses on registries created for one or more of the following purposes: to describe the natural history of disease, to determine clinical effectiveness or costeffectiveness of health care products and services, to measure or monitor safety and harm, and/or to measure quality of care.