Anne B. Cropp

The Seattle Heart Failure Model: Prediction of Survival in Heart Failure

Background— Heart failure has an annual mortality rate ranging from 5% to 75%. The purpose of the study was to develop and validate a multivariate risk model to predict 1-, 2-, and 3-year survival in heart failure patients with the use of easily obtainable characteristics relating to clinical status, therapy (pharmacological as well as devices), and laboratory parameters. Methods and Results— The Seattle Heart Failure Model was derived in a cohort of 1125 heart failure patients with the use of a multivariate Cox model. For medications and devices not available in the derivation database, hazard ratios were estimated from published literature. The model was prospectively validated in 5 additional cohorts totaling 9942 heart failure patients and 17 307 person-years of follow-up. The accuracy of the model was excellent, with predicted versus actual 1-year survival rates of 73.4% versus 74.3% in the derivation cohort and 90.5% versus 88.5%, 86.5% versus 86.5%, 83.8% versus 83.3%, 90.9% versus 91.0%, and 89.6% versus 86.7% in the 5 validation cohorts. For the lowest score, the 2-year survival was 92.8% compared with 88.7%, 77.8%, 58.1%, 29.5%, and 10.8% for scores of 0, 1, 2, 3, and 4, respectively. The overall receiver operating characteristic area under the curve was 0.729 (95% CI, 0.714 to 0.744). The model also allowed estimation of the benefit of adding medications or devices to an individual patients therapeutic regimen. Conclusions— The Seattle Heart Failure Model provides an accurate estimate of 1-, 2-, and 3-year survival with the use of easily obtained clinical, pharmacological, device, and laboratory characteristics.

Effect of Amlodipine on Morbidity and Mortality in Severe Chronic Heart Failure

BACKGROUND Previous studies have shown that calcium-channel blockers increase morbidity and mortality in patients with chronic heart failure. We studied the effect of a new calcium-channel blocker, amlodipine, in patients with severe chronic heart failure. METHODS We randomly assigned 1153 patients with severe chronic heart failure and ejection fractions of less than 30 percent to double-blind treatment with either placebo (582 patients) or amlodipine (571 patients) for 6 to 33 months, while their usual therapy was continued. The randomization was stratified on the basis of whether patients had ischemic or nonischemic causes of heart failure. The primary end point of the study was death from any cause and hospitalization for major cardiovascular events. RESULTS Primary end points were reached in 42 percent of the placebo group and 39 percent of the amlodipine group, representing a 9 percent reduction in the combined risk of fatal and nonfatal events with amlodipine (95 percent confidence interval, 24 percent reduction to 10 percent increase; P=0.31). A total of 38 percent of the patients in the placebo group died, as compared with 33 percent of those in the amlodipine group, representing a 16 percent reduction in the risk of death with amlodipine (95 percent confidence interval, 31 percent reduction to 2 percent increase; P=0.07). Among patients with ischemic heart disease, there was no difference between the amlodipine and placebo groups in the occurrence of either end point. In contrast, among patients with nonischemic cardiomyopathy, amlodipine reduced the combined risk of fatal and nonfatal events by 31 percent (P=0.04) and decreased the risk of death by 46 percent (P<0.001). CONCLUSIONS Amlodipine did not increase cardiovascular morbidity or mortality in patients with severe heart failure. The possibility that amlodipine prolongs survival in patients with nonischemic dilated cardiomyopathy requires further study.

Results of Bococizumab, A Monoclonal Antibody Against Proprotein Convertase Subtilisin/Kexin Type 9, from a Randomized, Placebo-Controlled, Dose-Ranging Study in Statin-Treated Subjects With Hypercholesterolemia

Bococizumab is a humanized monoclonal antibody binding proprotein convertase subtilisin/kexin type 9, which may be a potential therapeutic option for reducing low-density lipoprotein cholesterol (LDL-C) levels in patients with hypercholesterolemia. In this 24-week, multicenter, double-blind, placebo-controlled, dose-ranging study (NCT01592240), subjects with LDL-C levels≥80 mg/dl on stable statin therapy were randomized to Q14 days subcutaneous placebo or bococizumab 50, 100, or 150 mg or Q28 days subcutaneous placebo or bococizumab 200 or 300 mg. Doses of bococizumab were reduced if LDL-C levels persistently decreased to ≤25 mg/dl. The primary end point was the absolute change in LDL-C levels from baseline to week 12 after placebo or bococizumab administration. Continuation of bococizumab administration through to week 24 enabled the collection of safety data over an extended period. Of the 354 subjects randomized, 351 received treatment (placebo [n=100] or bococizumab [n=251]). The most efficacious bococizumab doses were 150 mg Q14 days and 300 mg Q28 days. Compared with placebo, bococizumab 150 mg Q14 days reduced LDL-C at week 12 by 53.4 mg/dl and bococizumab 300 mg Q28 days reduced LDL-C by 44.9 mg/dl; this was despite dose reductions in 32.5% and 34.2% of subjects at week 10 or 8, respectively. Pharmacokinetic/pharmacodynamic model-based simulation assuming no dose reductions predicted that bococizumab would lower LDL-C levels by 72.2 and 55.4 mg/dl, respectively. Adverse events were similar across placebo and bococizumab groups. Few subjects (n=7; 2%) discontinued treatment because of treatment-related adverse events. In conclusion, bococizumab significantly reduced LDL-C across all doses despite dose reductions in many subjects. Model-based simulations predicted greater LDL-C reduction in the absence of bococizumab dose reduction. The Q14 days regimen is being evaluated in phase 3 clinical trials.

Role of Cytokines in the Mechanism of Action of Amlodipine: The PRAISE Heart Failure Trial ☆

OBJECTIVES We sought to determine whether the beneficial effects of amlodipine in heart failure may be mediated by a reduction in tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) levels. We postulated that TNF-alpha and IL-6 levels may also have predictive value in patients with congestive heart failure (CHF). BACKGROUND The molecular mechanism for progression of CHF may involve cytokine overexpression. The effect of amlodipine on cytokine levels in patients with CHF is unknown. METHODS In the Prospective Randomized Amlodipine Survival Evaluation (PRAISE) trial, we used enzyme-linked immunosorbent assay to measure plasma levels of TNF-alpha in 92 patients and IL-6 in 62 patients in New York Heart Association functional classes III and IV randomized to receive amlodipine (10 mg/day) or placebo. Blood samples were obtained for cytokine measurement at baseline and at 8 and 26 weeks after enrollment. RESULTS The baseline amlodipine and placebo groups did not differ in demographics and cytokine levels. Mean (+/- SD) plasma levels of TNF-alpha were 5.69 +/- 0.32 pg/ml, and those of IL-6 were 9.23 +/- 1.26 pg/ml at baseline. These levels were elevated 6 and 10 times, respectively, compared with those of normal subjects (p < 0.001). Levels of TNF-alpha did not change significantly over the 26-week period (p = 0.69). However, IL-6 levels were significantly lower at 26 weeks in patients treated with amlodipine versus placebo (p = 0.007 by the Wilcoxon signed-rank test). An adverse event-CHF or death-occurred more commonly in patients with higher IL-6 levels. CONCLUSIONS Amlodipine lowers plasma IL-6 levels in patients with CHF. The beneficial effect of amlodipine in CHF may be due to a reduction of cytokines such as IL-6.

Effect of amlodipine on mode of death among patients with advanced heart failure in the praise trial

Investigations of calcium antagonists in patients with advanced heart failure have raised concern over an increased risk of worsening heart failure and heart failure deaths. We assessed the effect of amlodipine on cause-specific mortality in such patients enrolled in a randomized, double-blind, placebo-controlled trial. In total, 1,153 patients in New York Heart Association class IIIb or IV heart failure were randomized to receive amlodipine or placebo, along with angiotensin-converting enzyme inhibitors, diuretics, and digitalis. Over a median 14.5 months of follow-up, 413 patients died. Cardiovascular deaths accounted for 89% of fatalities, 50% of which were sudden deaths and 45% of which were due to pump failure, with fewer attributed to myocardial infarction (3.3%) or other cardiovascular causes (1.6%). Amlodipine treatment resulted in a greater relative reduction in sudden deaths (21%) than in pump failure deaths (6.6%) overall. When patients were classified by etiology of heart failure (ischemic or nonischemic), cause-specific mortality did not differ significantly between treatment groups in the ischemic stratum. In the nonischemic stratum, however, sudden deaths and pump failure deaths were reduced by 38% and 45%, respectively, with amlodipine. Thus, when added to digitalis, diuretics, and angiotensin-converting enzyme inhibitors in patients with advanced heart failure, amlodipine appears to have no effect on cause-specific mortality in ischemic cardiomyopathy, but both pump failure and sudden deaths appear to be decreased in nonischemic heart failure patients treated with amlodipine.

Circadian rhythm and sudden death in heart failure: results from Prospective Randomized Amlodipine Survival Trial.

OBJECTIVE The purpose of this study was to address the timing of sudden death in advanced heart failure patients. BACKGROUND Sudden death is a catastrophic event in cardiovascular disease. It has a circadian pattern prominent in the early AM, which has been thought to be due to a surge of sympathetic stimulation. We postulated that the distribution of events in advanced heart failure, with chronic sympathetic activation, would be more uniform implicating other potential mechanisms. METHODS We analyzed data from Prospective Randomized Amlodipine Survival Trial (PRAISE). Sudden deaths were analyzed by time of death in 4-h and 1-h blocks for uniformity of distribution in the entire cohort, and in the prespecified ischemic and nonischemic stratum. Further analyses were undertaken in the treatment groups of amlodipine and placebo, and among those receiving background therapy of aspirin and warfarin. RESULTS Sudden deaths in the overall cohort showed a nonuniform distribution with a PM peak but not an AM peak. The ischemic stratum also showed a PM peak, but sudden deaths within the nonischemic stratum were uniformly distributed. Neither amlodipine treatment nor aspirin or warfarin use altered the distribution. CONCLUSIONS Sudden death in advanced heart failure did not show an AM peak, suggesting that circadian sympathetic activation did not strongly influence these events. The PM peak noted is likely complex in origin and was not affected by antiischemic or antithrombotic medications.

Measuring the Incidence, Causes, and Repercussions of Protocol Amendments

Drug development companies frequently amend finalized clinical trial protocols. Yet the incidence, causes, and impact of protocol amendments have never been quantified. Tufts Center for the Study of Drug Development (Tufts CSDD) conducted a study, in collaboration with 17 large and midsized pharmaceutical and biotechnology companies, examining more than 3,400 clinical trial protocols across development phases and therapeutic areas. Data on protocol characteristics, the number of amendments, the nature and incidence of changes per amendment, the causes of amendments, and the time and cost to implement amendments were among those analyzed. Tufts CSDD found that more than 40% of protocols were amended prior to the first subject/first visit, and one third of amendments were avoidable. Each amended protocol had an average of 2.3 amendments resulting in 4 months of incremental time to implement. Protocol amendments translate into significant unplanned expense and delays for research sponsors and unexpected burden for investigative sites. These findings underscore the substantial impact of protocol amendments on drug development efficiency and present an opportunity to realize substantial cycle time and cost savings.

Should troponin and creatinine kinase be routinely measured after vascular surgery

The current guidelines for the evaluation and prediction of adverse cardiovascular events (CVEs) following vascular surgery in high-risk patients recommends serial electrocardiograms (ECGs) but not biomarkers such as cTn-I and CK-MB. The objective of this study was to determine whether biomarkers should be routinely measured in high-risk patients undergoing vascular surgery. A multicenter, prospective study with investigators blinded to core laboratory results was conducted. cTn-I and CK-MB were obtained on the day of surgery, as well as 24 hours, 72 hours and 120 hours after surgery, 24 hours prior to planned hospital discharge and at the onset of symptoms of a suspected CVE. The CVE was adjudicated by an endpoint committee using ECG, biomarker and symptoms data and was defined as cardiac death or myocardial infarction (MI) occurring up to 30 days after surgery. A total of 784 patients, with a mean age of 70.1 (SD ± 9.8), underwent vascular surgery. Of the 83 patients with a CVE, cTn-I was positive in 42 and CK-MB was positive in 29 on or before the day of the CVE. The number of patients not classified as having a CVE but positive for elevation of cTn-I or CK-MB was 64 and 20, respectively. cTn-I was more sensitive than CK-MB (50.6% versus 34.9%) for predicting a CVE. The optimum time for measuring cTn-I after surgery with the highest positive predictive value was 24 hours. In conclusion, these data support routine serial measurement of cTn-I after vascular surgery.