Christina Lindahl

High-Density Lipoprotein Cholesterol, High-Density Lipoprotein Particle Size, and Apolipoprotein A-I: Significance for Cardiovascular Risk: The IDEAL and EPIC-Norfolk Studies

OBJECTIVES This study was designed to assess the relationship of high-density-lipoprotein cholesterol (HDL-C), HDL particle size, and apolipoprotein A-I (apoA-I) with the occurrence of coronary artery disease (CAD), with a focus on the effect of very high values of these parameters. BACKGROUND High plasma levels of HDL-C and apoA-I are inversely related to the risk of CAD. However, recent data suggest that this relationship does not hold true for very high HDL-C levels, particularly when a preponderance of large HDL particles is observed. METHODS We conducted a post-hoc analysis of 2 prospective studies: the IDEAL (Incremental Decrease in End Points through Aggressive Lipid Lowering; n = 8,888) trial comparing the efficacy of high-dose to usual-dose statin treatment for the secondary prevention of cardiovascular events, and the EPIC (European Prospective Investigation into Cancer and Nutrition)-Norfolk case-control study, including apparently healthy individuals who did (cases, n = 858) or did not (control patients, n = 1,491) develop CAD during follow-up. In IDEAL, only HDL-C and apoA-I were available; in EPIC-Norfolk, nuclear magnetic resonance spectroscopy-determined HDL particle sizes were also available. RESULTS In the IDEAL study, higher HDL-C proved a significant major cardiac event risk factor following adjustment for age, gender, smoking, apoA-I, and apoB. A similar association was observed for HDL particle size in EPIC-Norfolk. Increased risk estimates were particularly present in the high ends of the distributions. In contrast, apoA-I remained negatively associated across the major part of its distribution in both studies. CONCLUSIONS When apoA-I and apoB are kept constant, HDL-C and HDL particle size may confer risk at very high values. This does not hold true for very high levels of apoA-I at fixed levels of HDL-C and apoB. These findings may have important consequences for assessment and treatment of CAD risk.

Total Cardiovascular Disease Burden: Comparing Intensive With Moderate Statin Therapy: Insights From the IDEAL (Incremental Decrease in End Points Through Aggressive Lipid Lowering) Trial

OBJECTIVES This post-hoc analysis of the IDEAL (Incremental Decrease in End Points Through Aggressive Lipid Lowering) trial was designed to assess the comparative treatment efficacy of high-dose atorvastatin and usual-dose simvastatin for the prevention of events subsequent to the first event, using the Wei, Lin, and Weissfeld method. BACKGROUND Time-to-first-event analysis of data is frequently utilized to provide efficacy outcome information in coronary heart disease prevention trials. However, during the course of such long-term trials, a large number of events occur subsequent to the first event, the analysis of which will be precluded by this approach. METHODS The Wei, Lin, and Weissfeld method allows the analysis of repeated occurrence of events of the same type or of entirely different natures. It regards the recurrence times as multivariate event (failure) times, and models the marginal (individual) distribution for each event with the Cox proportional hazards model. RESULTS In the IDEAL trial, compared with patients taking simvastatin 20 to 40 mg daily, patients receiving atorvastatin 80 mg daily had their relative risk of a first cardiovascular event reduced by 17% (p < 0.0001), of a second by 24% (p < 0.0001), of a third by 19% (p = 0.035), of a fourth by 24% (p = 0.058), and of a fifth by 28% (p = 0.117). CONCLUSIONS Our results indicate that intensive statin therapy continues to be more effective than standard statin therapy, even beyond the first event, and suggest that clinicians should not hesitate to prescribe high-dose statin therapy for patients experiencing multiple recurrent cardiovascular events.

Comparison of Efficacy and Safety of Atorvastatin (80 mg) to Simvastatin (20 to 40 mg) in Patients Aged <65 Versus ≥65 Years With Coronary Heart Disease (from the Incremental DEcrease through Aggressive Lipid Lowering [IDEAL] Study)

The efficacy and safety of atorvastatin (80 mg/day) versus simvastatin (20 to 40 mg/day) in older (age >or=65 years) versus younger (<65 years) patients were assessed in a prespecified secondary analysis of the 8,888 patients with myocardial infarction in the IDEAL trial, a randomized open-label study. Several cardiovascular end points were evaluated, including the occurrence of a first major coronary event (MCE; nonfatal myocardial infarction, coronary heart disease death, or resuscitated cardiac arrest), the primary end point of the trial, and occurrence of any cardiovascular event (MCE, stroke, revascularization, unstable angina, congestive heart failure, and peripheral artery disease). Although there were no significant interactions between age and treatment, the magnitude of effect in favor of atorvastatin was higher in younger versus older patients (occurrence of first MCE, hazard ratio [HR] 0.80, 95% confidence interval [CI] 0.66 to 0.98; and HR 0.95, 95% CI 0.80 to 1.15, respectively; occurrence of any cardiovascular (CV) event, HR 0.80, 95% CI 0.71 to 0.89; and HR 0.88, 95% CI 0.79 to 0.99, respectively). These results were likely influenced by adherence, which was lower in older patients and those receiving atorvastatin compared with those receiving simvastatin. Rates of any reported serious adverse event were higher in older patients, but did not differ between the 2 statin groups. In conclusion, except for any CV events in the older group, significant reductions in primary and secondary end points were observed only in patients <65 years of age. The safety of atorvastatin (80 mg) and simvastatin (20 to 40 mg) was similar in patients aged <65 and >65 years with stable coronary disease.

Lipoprotein predictors of cardiovascular events in statin-treated patients with coronary heart disease. Insights from the Incremental Decrease in End-points through Aggressive Lipid-lowering Trial (IDEAL)

Background. Few studies have looked into the ability of measurements of apolipoprotein B (apoB) and apolipoprotein A-1 (apoA-1) or apoB/apoA-1 to predict new coronary heart disease (CHD) events in patients with CHD on statin treatment. Aims. In the IDEAL trial, to compare lipoprotein components to predict CHD events and to what degree differences in those parameters could explain the observed outcome. Methods. We compared the ability of treatment with atorvastatin 80 mg/day to that of simvastatin 20–40 mg/day to prevent CHD events in patients with CHD and used Cox regression models to study the relationships between on-treatment levels of lipoprotein components to subsequent major coronary events (MCE). Findings. Variables related to low-density lipoprotein cholesterol (LDL-C) carried more predictive information than those related to high-density lipoprotein cholesterol (HDL-C), but LDL-C was less predictive than both non-HDL-C and apoB. The ratio of apoB to apoA-1 was most strongly related to MCE. However, for estimating differences in relative risk reduction between the treatment groups, apoB and non-HDL-C were the strongest predictors. Interpretation. The on-treatment level of apoB/apoA-1 was the strongest predictor of MCE in the pooled patient population, whereas apoB and non-HDL-C were best able to explain the difference in outcome between treatment groups. Measurements of apoB and apoA-1 should be more widely available for routine clinical assessments.

Comparison of Atorvastatin 80 mg/day Versus Simvastatin 20 to 40 mg/day on Frequency of Cardiovascular Events Late (Five Years) After Acute Myocardial Infarction (from the Incremental Decrease in End Points Through Aggressive Lipid Lowering [IDEAL] Trial)

Previous studies have demonstrated that benefits of intensive statin therapy compared to standard statin therapy begin shortly after an acute event and are continued up to 2 years of follow-up. However, whether efficacy and safety of intensive statin therapy in patients with a recent cardiac event are maintained in longer-term follow-up has not been evaluated. We conducted a post hoc analysis of a subgroup of 999 patients who had a first acute myocardial infarction (MI) <2 months before randomization in a prospective, open-label, blinded end-point evaluation trial of 8,888 patients with a history of MI that compared intensive statin therapy (atorvastatin 80 mg) to standard statin therapy (simvastatin 20 to 40 mg) over approximately 5 years of follow-up. We analyzed the same composite end point used in the Pravastatin or Atorvastatin Evaluation and Infection Therapy (PROVE IT) trial (death, MI, hospitalization for unstable angina, revascularization, and stroke). Rates of the composite end point were 44.7% (n = 226) in the simvastatin group and 37.9% (n = 187) in the atorvastatin group (hazard ratio 0.82, 95% confidence interval 0.67 to 0.99, p = 0.04). Although statistical power was smaller than that of the PROVE IT trial, the relative risk decrease observed at 5 years is consistent with that in the 2-year follow-up in PROVE IT. The 2 treatment regimens were well tolerated. In conclusion, our analysis provides support for the strategy of placing patients with recent MI on intensive statin therapy and maintaining the high dose over the long term, beyond 2 years.

Cardiovascular outcomes and their relationships to lipoprotein components in patients with and without chronic kidney disease: results from the IDEAL trial

Abstract.  Holme I, Fayyad R, Faergeman O, Kastelein JJP, Olsson AG, Tikkanen MJ, Larsen ML, Lindahl C, Holdaas H, Pedersen TR, On behalf of the Incremental Decrease in End Points Through Aggressive Lipid Lowering Study Group (Centre of Preventive Medicine, Oslo, Norway; Århus University Hospital, Århus, Denmark; Academic Hospital Amsterdam, Amsterdam, The Netherlands; University Hospital, Linköping, Sweden; Helsinki University Central Hospital, Helsinki, Finland; Oslo University Hospital, Rikshospitalet, Oslo, Norway; Pfizer Sweden, Sollentuna, Sweden; and Pfizer Inc., New York, NY, USA). Cardiovascular outcomes and their relationships to lipoprotein components in patients with and without chronic kidney disease: Results from the IDEAL trial. J Intern Med 2010; 267:567–575.

Adherence-adjusted efficacy with intensive versus standard statin therapy in patients with acute myocardial infarction in the IDEAL study

Background The Incremental Decrease in End Points through Aggressive Lipid Lowering trial showed that the primary endpoint major coronary event was reduced by 11% (0.78-1.01) using atorvastatin 80 mg versus simvastatin 20-40 mg in patients with coronary heart disease (P = 0.07). Adherence was high in both treatment groups but significantly higher in patients treated with simvastatin. Design The Incremental Decrease in End Points through Aggressive Lipid Lowering was a prescription trial with a prospective randomized open label endpoint evaluation. Methods and results Adherence was calculated as exposure time on prescribed drugs divided by total follow-up time until death or end of follow-up and was a potential confounder. Adjusting for categorical adherence below or above 80% by two methods revealed that the relative risk reduction of the primary endpoint was more in the region of 15% (P = 0.02) than 11% as found unadjusted. Censoring at the first occurrence of a cardiovascular event rather than at death increased this estimate to 17% (P = 0.02). Noncardiovascular mortality was reduced on atorvastatin treatment by 21% (1-37%) after adjustment for adherence, whereas such reduction was not observed for cardiovascular mortality. Conclusion This study found that the difference in adherence between treatment groups may have underestimated the true effect of the treatment differential. Usage of prospective randomized open label endpoint evaluation design should be carefully considered when well-known treatments are compared with rather new ones and especially in segments where patients could be more vulnerable, as in the elderly. Nonadherers in a clinical trial may be at especially high risk of fatal and nonfatal endpoints from various diseases and should be carefully monitored.

Congestive heart failure is associated with lipoprotein components in statin-treated patients with coronary heart disease Insights from the Incremental Decrease in End points Through Aggressive Lipid Lowering Trial (IDEAL).

BACKGROUND Very few, if any, studies have assessed the ability of apolipoproteins to predict new-onset of congestive heart failure (HF) in statin-treated patients with coronary heart disease (CHD). AIMS To employ the Incremental Decrease in End points Through Aggressive Lipid Lowering Trial (IDEAL) study database to assess the association of on-treatment lipoprotein components with prediction of HF events and to compare their predictive value with that of established risk factors such as hypertension and diabetes. METHODS We used Cox regression models to study the relationships between on-treatment levels of apolipoproteins A1 and B to subsequent HF. Chi square information value from the log likelihood was used to compare the predictive value of lipoprotein components with established risk factors of HF. FINDINGS In the IDEAL study, on-treatment apolipoproteins proved to be associated with the occurrence of new-onset HF. Variables related to low-density lipoprotein cholesterol (LDL-C) carried less predictive information than those related to high-density lipoprotein cholesterol (HDL-C), and apoA-1 was the single variable most strongly associated with HF. LDL-C was less predictive than both non-HDL-C (total cholesterol minus HDL-C) and apoB. The ratio of apoB to apoA-1 was most strongly related to HF after adjustment for potential confounders, among which diabetes had a stronger correlation with HF than did hypertension. ApoB/apoA-1 carried approximately 2.2 times more of the statistical information value than that of diabetes. Calculation of the net reclassification improvement index revealed that about 3.7% of the patients had to be reclassified into more correct categories of risk once apoB/apoA-1 was added to the adjustment factors. The reduction in risk by intensive lipid-lowering treatment as compared to usual-dose simvastatin was well predicted by the difference in apoB/apoA-1 on-treatment levels. INTERPRETATION The on-treatment ratio of apoB/apoA-1 was the strongest predictor of HF in CHD patients of both IDEAL treatment arms combined, mostly driven by the strong association with apoA-1, whereas LDL-C and non-HDL-C were less able to predict HF outcome. The predictive information value contained within apoB/apoA-1 was about 2.2 times more than that of diabetes. Between-treatment group differences in HF were to a significant extent explained by on-treatment differences in apoB/apoA-1, mostly through the changes in apoB. We argue therefore, on-treatment lipoprotein components contribute to the overall future risk of HF in statin-treated patients with CHD.

LDL cholesterol goals and cardiovascular risk during statin treatment: the IDEAL study

Aims: We assessed the proportion of patients treated with either simvastatin 20 or 40 mg or atorvastatin 80 mg who achieved low-density lipoprotein cholesterol (LDL-C) goals of 2.5 or 2.0 mmol/l in the Incremental Decrease in End Points Through Aggressive Lipid Lowering (IDEAL) study. We explored how lipoprotein components related to cardiovascular disease (CVD) outcomes in these groups. Methods and results: For subjects who reached on-treatment LDL-C goals, Cox regression models were used to assess the ability of lipoprotein components to predict CVD events. Treatment with simvastatin or atorvastatin resulted in 40 per cent and 80 per cent of patients, respectively, reaching the 2.5 mmol/l goal and 12 per cent and 52 per cent, respectively, reaching the 2.0 mmol/l goal, after 1 year (all p < 0.001 between groups). Adjusting for baseline LDL-C levels, hazard ratio (HR) for those reaching 2.0–2.5 mmol/l LDL-C versus those reaching <2.0 mmol/l was 1.16 (95% confidence interval [CI], 1.02–1.33, p = 0.023). An increase of the apolipoprotein B/A1 (apoB/A1) ratio by 1 standard deviation in participants who reached 2.0 mmol/l showed a HR for CVD of 1.14 (95% CI, 1.04–1.25, p = 0.004). Conclusion: More CVD patients treated with atorvastatin than simvastatin achieved either LDL-C goal and those reaching the 2.0 mmol/l goal exhibited significantly less CVD than those only reaching 2.5 mmol/l. In those reaching the 2.0 mmol/l goal, the apoB/A1 ratio still bears a relation to CVD outcome. The use of apoB/A1 ratio may provide additional predictive value to that of LDL-C.

Abstract: P824 CAN LIPID/APOLIPOPROTEIN FACTORS ACCOUNT FOR RESIDUAL RISK IN PATIENTS ATTAINING CURRENT LDL-C TARGETS?

CAN LIPID/APOLIPOPROTEIN FACTORS ACCOUNT FOR RESIDUAL RISK IN PATIENTS ATTAINING CURRENT LDL-C TARGETS?