Alfred Callahan

Effects of Intense Low-Density Lipoprotein Cholesterol Reduction in Patients With Stroke or Transient Ischemic Attack The Stroke Prevention by Aggressive Reduction in Cholesterol Levels (SPARCL) Trial

Background and Purpose— The intention-to-treat analysis of data from the placebo-controlled Stroke Prevention by Aggressive Reduction in Cholesterol Levels (SPARCL) trial found 80 mg atorvastatin per day reduced the risk of stroke and major coronary events in patients with recent stroke or transient ischemic attack. This benefit was present despite only a 78% net difference in adherence to randomized treatment over the course of the trial. In this exploratory analysis, our aim was to evaluate the benefit and risks associated with achieving a ≥50% low-density lipoprotein cholesterol (LDL-C) reduction from baseline. Methods— This post hoc analysis was based on 55 045 LDL-C measurements among the 4731 patients enrolled in SPARCL (average, 11.6 measurements per patient) during a mean follow-up of 4.9 years. At each postrandomization LDL-C assessment, percent change in LDL-C from baseline for each patient was classified as no change or increase from baseline (32.7% of measurements), <50% LDL-C reduction (39.4%), or ≥50% reduction (27.9%). Results— Compared with no change or an increase in LDL-C, analysis of time-varying LDL-C change showed that patients with ≥50% LDL-C reduction had a 31% reduction in stroke risk (hazard ratio, 0.69, 95% CI, 0.55 to 0.87, P=0.0016), a 33% reduction in ischemic stroke (P=0.0018), no statistically significant increase in hemorrhagic stroke (P=0.8864), and a 37% reduction in major coronary events (P=0.0323). There was no increase in the incidence of myalgia or rhabdomyolysis. Persistent liver enzyme elevations were more frequent in the group with ≥50% LDL-C reduction. Conclusions— As compared with having no change or an increase in LDL-C, achieving a ≥50% lowering was associated with a greater reduction in the risk of stroke and major coronary events with no increase in brain hemorrhages.

Atorvastatin Reduces the Risk of Cardiovascular Events in Patients With Carotid Atherosclerosis: A Secondary Analysis of the Stroke Prevention by Aggressive Reduction in Cholesterol Levels (SPARCL) Trial

Background and Purpose— The Stroke Prevention by Aggressive Reduction in Cholesterol Levels (SPARCL) trial found that treatment with atorvastatin 80 mg per day reduced the risk of stroke and cardiovascular events in patients with a recent transient ischemic attack (TIA) or stroke. We hypothesized this benefit would be greatest in the subgroup of patients with carotid stenosis. Methods— The SPARCL trial randomized patients with TIA or stroke within 1 to 6 months without known coronary heart disease (CHD) and low-density lipoprotein cholesterol 100 to 190 mg/dL to treatment with atorvastatin 80 mg per day or placebo. Investigators identified subjects as having carotid stenosis not requiring revascularization at the time of randomization. Of the total SPARCL population, 1007 were documented as having carotid stenosis at baseline, 3271 did not, and the status of 453 was unknown. Results— We found no heterogeneity in the treatment effect for the SPARCL primary (fatal and nonfatal stroke) and secondary end points between the group with and without carotid stenosis. The group with carotid artery stenosis had greater benefit when all cerebro- and cardiovascular events were combined. In the group with carotid artery stenosis, treatment with atorvastatin was associated with a 33% reduction in the risk of any stroke (hazard ratio [HR] 0.67, 95% confidence interval [CI] 0.47, 0.94; P=0.02), and a 43% reduction in risk of major coronary events (HR 0.57, 95% CI 0.32, 1.00; P=0.05). Later carotid revascularization was reduced by 56% (HR 0.44, 95% CI 0.24, 0.79; P=0.006) in the group randomized to atorvastatin. Conclusion— Consistent with the overall results of the SPARCL intention to treat population, intense lipid lowering with atorvastatin reduced the risk of cerebro- and cardiovascular events in patients with and without carotid stenosis. The carotid stenosis group may have greater benefit.

Results of the Stroke Prevention by Aggressive Reduction in Cholesterol Levels (SPARCL) Trial by Stroke Subtypes

Background and Purpose— The SPARCL trial showed that atorvastatin 80 mg/d reduces the risk of stroke and other cardiovascular events in patients with recent stroke or transient ischemic attack (TIA). We tested the hypothesis that the benefit of treatment varies according to index event stroke subtype. Methods— Subjects with stroke or TIA without known coronary heart disease were randomized to atorvastatin 80 mg/d or placebo. The SPARCL primary end point was fatal or nonfatal stroke. Secondary end points included major cardiovascular events (MCVE; stroke plus major coronary events). Cox regression models testing for an interaction with treatment assignment were used to explore potential differences in efficacy based on stroke subtype. Results— For subjects randomized to atorvastatin versus placebo, a primary end point occurred in 13.1% versus 18.6% of those classified as having large vessel disease (LVD, 15.8% of 4,731 participants), in 13.1% versus 15.5% of those with small vessel disease (SVD, 29.8%), in 11.2% versus 12.7% of those with ischemic stroke of unknown cause (21.5%), in 7.6% versus 8.8% of those with TIA (30.9%), and in 22.2% versus 8.3% of those with hemorrhagic stroke (HS, 2%) at baseline. There was no difference in the efficacy of treatment for either the primary end point (LVD hazard ratio [HR] 0.70, 95% confidence interval [CI] 0.49 to 1.02, TIA HR 0.81, CI 0.57 to 1.17, SVD HR 0.85, CI 0.64 to 1.12, unknown cause HR 0.87, CI 0.61 to 1.24, HS HR 3.24, CI 1.01 to 10.4; P for heterogeneity=0.421), or MCVEs (P for heterogeneity=0.360) based on subtype of the index event. As compared to subjects with LVD strokes, those with SVD had similar MCVE rates (19.2% versus 18.5% over the course of the trial), and similar overall reductions in stroke and MCVEs. Conclusions— Atorvastatin 80 mg/d is similarly efficacious in preventing strokes and other cardiovascular events, irrespective of baseline ischemic stroke subtype.

Statin Treatment and Stroke Outcome in the Stroke Prevention by Aggressive Reduction in Cholesterol Levels (SPARCL) Trial

Background and Purpose— Laboratory experiments suggest statins reduce stroke severity and improve outcomes. The Stroke Prevention by Aggressive Reduction in Cholesterol Levels (SPARCL) trial was a placebo-controlled, randomized trial designed to determine whether treatment with atorvastatin reduces strokes in subjects with recent stroke or transient ischemic attack (n=4731). We analyzed SPARCL trial data to determine whether treatment favorably shifts the distribution of severities of ischemic cerebrovascular outcomes. Methods— Severity was assessed with the National Institutes of Health Stroke Scale, Barthel Index, and modified Rankin Scale score at enrollment (1 to 6 months after the index event) and 90 days poststroke in subjects having a stroke during the trial. Results— Over 4.9 years, strokes occurred in 576 subjects. There were reductions in fatal, severe (modified Rankin Scale score 5 or 4), moderate (modified Rankin Scale score 3 or 2), and mild (modified Rankin Scale score 1 or 0) outcome ischemic strokes and transient ischemic attacks and an increase in the proportion of event-free subjects randomized to atorvastatin (P<0.001 unadjusted and adjusted). Results were similar for all outcome events (ischemic and hemorrhagic, P<0.001 unadjusted and adjusted) with no effect on outcome hemorrhagic stroke severity (P=0.174 unadjusted, P=0.218 adjusted). If the analysis is restricted to those having an outcome ischemic stroke (ie, excluding those having a transient ischemic attack or no event), there was only a trend toward lesser severity with treatment based on the modified Rankin Scale score (P=0.0647) with no difference based on the National Institutes of Health Stroke Scale or Barthel Index. Conclusion— The present exploratory analysis suggests that the outcome of recurrent ischemic cerebrovascular events might be improved among statin users as compared with nonusers.

Relative Effects of Statin Therapy on Stroke and Cardiovascular Events in Men and Women. Secondary Analysis of the Stroke Prevention by Aggressive Reduction in Cholesterol Levels (SPARCL) Study

Background and Purpose— In SPARCL, treatment with atorvastatin 80 mg daily reduced stroke risk in patients with recent stroke or TIA and no known coronary heart disease by 16% versus placebo over 4.9 years of follow-up. The purpose of this secondary analysis was to determine whether men and women similarly benefited from randomization to statin treatment. Methods— The effect of sex on treatment-related reductions in stroke and other cardiovascular outcomes were analyzed with Cox regression modeling testing for sex by treatment interactions. Results— Women (n=1908) constituted 40% of the SPARCL study population. At baseline, men (n=2823) were younger (62.0±0.21versus 63.9±0.27 years), had lower systolic BPs (138.1±0.35 versus 139.5±0.47 mm Hg), higher diastolic BPs (82.2±0.20 versus 81.0±0.25 mm Hg), more frequently had a history of smoking (73% versus 38%), and had lower total cholesterol (207.0±0.54 versus 218.9±0.67 mg/dL) and LDL-C levels (132±0.45 versus 134±0.57 mg/dL) than women. Use of antithrombotics and antihypertensives were similar. After prespecified adjustment for region, entry event, time since event, and age, there were no sex by treatment interactions for the combined risk of nonfatal and fatal stroke (treatment Hazard Ratio, HR=0.84, 95% CI 0.68, 1.02 in men versus HR=0.84, 95% CI 0.63, 1.11 in women; treatment×sex interaction P=0.99), major cardiac events (HR=0.61, 95% CI 0.42, 0.87 in men versus HR=0.76, 95% CI 0.48, 1.21 in women; P=0.45), major cardiovascular events (HR=0.78, 95% CI 0.65, 0.93 in men versus HR=0.84, 95% CI 0.65, 1.07 in women; P=0.63), revascularization procedures (HR=0.50, 95% CI 0.37, 0.67 in men versus HR=0.76, 95% CI 0.46, 1.24 in women; P=0.17), or any CHD event (HR=0.54, 95% CI 0.41, 0.72 in men versus 0.67 95% CI 0.46, 0.98 in women; P=0.40). Conclusion— Stroke and other cardiovascular events are similarly reduced with atorvastatin 80 mg/d in men and women with recent stroke or TIA.

Baseline blood pressure, low- and high-density lipoproteins, and triglycerides and the risk of vascular events in the Stroke Prevention by Aggressive Reduction in Cholesterol Levels (SPARCL) trial

OBJECTIVE To explore the relative contributions of baseline systolic blood pressure (SBP) and diastolic blood pressure (DBP) and lipoproteins on the risk of recurrent stroke or first major cardiovascular event (MCVE) and their potential impact on the benefit of statin treatment. METHODS AND RESULTS The SPARCL trial randomized 4731 patients with recent stroke or transient ischemic attack (TIA) and no known coronary heart disease and LDL-C between 100 and 190 mg/dL to either atorvastatin 80 mg/d or placebo. Baseline assessment included SBP, DBP and measurements of low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C), and triglyceride levels. After 4.9 years of follow-up, there were 575 primary end points (fatal and nonfatal stroke), including 491 ischemic strokes, and 740 MCVEs (stroke plus myocardial infarction and vascular death). Cox regression models analysis showed a trend (P>0.05 and P<0.10) for higher SBP but not DBP to be associated with an outcome stroke with only SBP associated with MCVE. Only baseline low HDL-C was associated with an outcome stroke. Baseline HDL-C, triglycerides, and LDL/HDL ratio were each associated with MCVEs. There were no interactions between any of these baseline variables and the effect of treatment on outcome strokes. CONCLUSIONS In patients with recent stroke or TIA and no coronary heart disease, only lower baseline HDL-C predicted the risk of recurrent stroke with HDL-C, triglycerides, and LDL/HDL ratio associated with MCVE. Atorvastatin treatment was similarly effective regardless of baseline lipoprotein levels.

Relative and Cumulative Effects of Lipid and Blood Pressure Control in the Stroke Prevention by Aggressive Reduction in Cholesterol Levels Trial

Background and Purpose— The relative contributions of on-treatment low- and high-density lipoprotein cholesterol (LDL-C, HDL-C), triglycerides, and blood pressure (BP) control on the risk of recurrent stroke or major cardiovascular events in patients with stroke is not well defined. Methods— We randomized 4731 patients with recent stroke or transient ischemic attack and no known coronary heart disease to atorvastatin 80 mg per day or placebo. Results— After 4.9 years, at each level of LDL-C reduction, subjects with HDL-C value above the median or systolic BP below the median had greater reductions in stroke and major cardiovascular events and those with a reduction in triglycerides above the median or diastolic BP below the median showed similar trends. There were no statistical interactions between on-treatment LDL-C, HDL-C, triglycerides, and BP values. In a further exploratory analysis, optimal control was defined as LDL-C <70 mg per deciliter, HDL-C >50 mg per deciliter, triglycerides <150 mg per deciliter, and SBP/DBP <120/80 mm Hg. The risk of stroke decreased with as the level of control increased (hazard ratio [95% confidence interval] 0.98 [0.76 to 1.27], 0.78 [0.61 to 0.99], 0.62 [0.46 to 0.84], and 0.35 [0.13 to 0.96]) for those achieving optimal control of 1, 2, 3, or 4 factors as compared to none, respectively. Results were similar for major cardiovascular events. Conclusions— We found a cumulative effect of achieving optimal levels of LDL-C, HDL-C, triglycerides, and BP on the risk of recurrent stroke and major cardiovascular events. The protective effect of having a higher HDL-C was maintained at low levels of LDL-C.

EFFECT OF ATORVASTATIN IN ELDERLY PATIENTS WITH A RECENT STROKE OR TRANSIENT ISCHEMIC ATTACK

Background: It is unclear whether patients age 65 years and over with a recent stroke or TIA benefit from statin treatment to a similar degree as younger patients. Methods: The 4,731 patient cohort in the SPARCL study was divided into an elderly group (65 and over) and a younger group. The primary endpoint (fatal or nonfatal stroke) and secondary endpoints were analyzed, with calculation of the hazard ratio (HR) and p values from a Cox regression model. Results: There were 2,249 patients in the elderly group and 2,482 in the younger group. The baseline LDL (133 mg/dL) and total cholesterol were comparable in the two groups. The elderly and younger groups had a 61.4 mg/dL and 58.7 mg/dL decrease in mean LDL during the trial. The primary endpoint was reduced by 26% in younger patients (HR 0.74, 0.57–0.96, p = 0.02) and by 10% in elderly subjects (HR 0.90, 0.73–1.11, p = 0.33). A test of heterogeneity for a treatment–age interaction was not significant (p = 0.52). The risk of stroke or TIA (HR 0.79, p = 0.01), major coronary events (HR 0.68, p = 0.035), any coronary heart disease event (HR 0.61, p = 0.0006), and revascularization procedures (HR 0.55, p = 0.0005) was reduced in the elderly group. Conclusions: There was no heterogeneity in the stroke reduction seen with atorvastatin in the elderly and younger groups. Cardiac events and revascularization procedures were also lower in both the elderly and younger subgroups treated with atorvastatin. These results support the use of atorvastatin in elderly patients with recent stroke or TIA. CHD = coronary heart disease; LDL-C = low-density lipoprotein cholesterol; RRR = relative risk reduction; SPARCL = Stroke Prevention by Aggressive Reduction in Cholesterol Levels.

Risk of Stroke and Cardiovascular Events After Ischemic Stroke or Transient Ischemic Attack in Patients With Type 2 Diabetes or Metabolic Syndrome: Secondary Analysis of the Stroke Prevention by Aggressive Reduction in Cholesterol Levels (SPARCL) Trial

OBJECTIVE To perform a secondary analysis of the Stroke Prevention by Aggressive Reduction in Cholesterol Levels (SPARCL) trial, which tested the effect of treatment with atorvastatin in reducing stroke in subjects with a recent stroke or transient ischemic attack, to explore the effects of treatment in subjects with type 2 diabetes mellitus or metabolic syndrome (MetS). METHODS The 4731 subjects enrolled in the SPARCL trial were classified as having type 2 diabetes mellitus at enrollment (n = 794), MetS retrospectively (n = 642), or neither diabetes nor MetS (n = 3295, the reference group) based on data collected at baseline. Cox regression models were used to determine whether the effect of treatment on the primary end point (combined risk of nonfatal and fatal stroke) and secondary end points (major coronary events, major cardiovascular events, any coronary heart disease event, and any revascularization procedure) varied based on the presence of type 2 diabetes mellitus or MetS. RESULTS Subjects with type 2 diabetes mellitus had increased risks of stroke (hazard ratio [HR] = 1.62; 95% confidence interval [CI], 1.33-1.98; P < .001), major cardiovascular events (HR = 1.66; 95% CI, 1.39-1.97; P < .001), and revascularization procedures (HR = 2.39; 95% CI, 1.78-3.19; P < .001) compared with the reference group. Subjects with MetS were not at increased risk for stroke (P = .78) or major cardiovascular events (P = .38) but more frequently had revascularization procedures (HR = 1.78; 95% CI, 1.26-2.5; P = .001). There were no treatment × subgroup interactions for the SPARCL primary end point (P = .47). CONCLUSIONS The SPARCL subjects with type 2 diabetes were at higher risk for recurrent stroke and cardiovascular events. This exploratory analysis found no difference in the effect of statin treatment in reducing these events in subjects with or without type 2 diabetes or MetS. Trial Registration clinicaltrials.gov Identifier: NCT00147602.

Coronary Heart Disease Risk in Patients With Stroke or Transient Ischemic Attack and No Known Coronary Heart Disease Findings From the Stroke Prevention by Aggressive Reduction in Cholesterol Levels (SPARCL) Trial

Background and Purpose— Noncoronary forms of atherosclerosis (including transient ischemic attacks or stroke of carotid origin or >50% stenosis of the carotid artery) are associated with a 10-year vascular risk of >20% and are considered as a coronary heart disease (CHD) -risk equivalent from the standpoint of lipid management. The Stroke Prevention by Aggressive Reduction in Cholesterol Levels (SPARCL) trial included patients with stroke or transient ischemic attack and no known CHD regardless of the presence of carotid atherosclerosis. We evaluated the risk of developing clinically recognized CHD in SPARCL patients. Methods— A total of 4731 patients (mean age, 63 years) was randomized to 80 mg/day atorvastatin placebo. The rates of major coronary event, any CHD event, and any revascularization procedure were evaluated. Results— After 4.9 years of follow-up, the risks of a major coronary event and of any CHD end point in the placebo group were 5.1% and 8.6%, respectively. The rate of outcome of stroke decreased over time, whereas the major coronary event rate was stable. Relative to those having a large vessel-related stroke at baseline, those having a transient ischemic attack, hemorrhagic stroke, small vessel stroke, or a stroke of unknown cause had similar absolute rates for a first major coronary event and for any CHD event; transient ischemic attack, small vessel, and unknown cause groups had lower absolute revascularization procedure rates. Major coronary event, any CHD event, and any revascularization procedure rates were similarly reduced in all baseline stroke subtypes in the atorvastatin arm compared with placebo with no heterogeneity between groups. Conclusion— CHD risk can be substantially reduced by atorvastatin therapy in patients with recent stroke or transient ischemic attack regardless of stroke subtype.