Effects of statin therapy on diagnoses of new-onset diabetes and worsening glycaemia in large-scale randomised blinded statin trials: an individual participant data meta-analysis

BACKGROUND

Previous meta-analyses of summary data from randomised controlled trials have shown that statin therapy increases the risk of diabetes, but less is known about the size or timing of this effect, or who is at greatest risk. We aimed to address these gaps in knowledge through analysis of individual participant data from large, long-term, randomised, double-blind trials of statin therapy.

METHODS

We conducted a meta-analysis of individual participant data from randomised controlled trials of statin therapy that participated in the CTT Collaboration. All double-blind randomised controlled trials of statin therapy of at least 2 years' scheduled duration and with at least 1000 participants were eligible for inclusion in this meta-analysis. All recorded diabetes-related adverse events, treatments, and measures of glycaemia were sought from eligible trials. Meta-analyses assessed the effects of allocation to statin therapy on new-onset diabetes (defined by diabetes-related adverse events, use of new glucose-lowering medications, glucose concentrations, or HbA1c values) and on worsening glycaemia in people with diabetes (defined by complications of glucose control, increased use of glucose-lowering medication, or HbA1c increase of ≥0·5%). Standard inverse-variance-weighted meta-analyses of the effects on these outcomes were conducted according to a prespecified protocol.

FINDINGS

Of the trials participating in the CTT Collaboration, 19 trials compared statin versus placebo (123 940 participants, 25 701 [21%] with diabetes; median follow-up of 4·3 years), and four trials compared more versus less intensive statin therapy (30 724 participants, 5340 [17%] with diabetes, median follow-up of 4·9 years). Compared with placebo, allocation to low-intensity or moderate-intensity statin therapy resulted in a 10% proportional increase in new-onset diabetes (2420 of 39 179 participants assigned to receive a statin [1·3% per year] vs 2214 of 39 266 participants assigned to receive placebo [1·2% per year]; rate ratio [RR] 1·10, 95% CI 1·04-1·16), and allocation to high-intensity statin therapy resulted in a 36% proportional increase (1221 of 9935 participants assigned to receive a statin [4·8% per year] vs 905 of 9859 participants assigned to receive placebo [3·5% per year]; 1·36, 1·25-1·48). For each trial, the rate of new-onset diabetes among participants allocated to receive placebo depended mostly on the proportion of participants who had at least one follow-up HbA1c measurement; this proportion was much higher in the high-intensity than the low-intensity or moderate-intensity trials. Consequently, the main determinant of the magnitude of the absolute excesses in the two types of trial was the extent of HbA1c measurement rather than the proportional increase in risk associated with statin therapy. In participants without baseline diabetes, mean glucose increased by 0·04 mmol/L with both low-intensity or moderate-intensity (95% CI 0·03-0·05) and high-intensity statins (0·02-0·06), and mean HbA1c increased by 0·06% (0·00-0·12) with low-intensity or moderate-intensity statins and 0·08% (0·07-0·09) with high-intensity statins. Among those with a baseline measure of glycaemia, approximately 62% of new-onset diabetes cases were among participants who were already in the top quarter of the baseline distribution. The relative effects of statin therapy on new-onset diabetes were similar among different types of participants and over time. Among participants with baseline diabetes, the RRs for worsening glycaemia were 1·10 (1·06-1·14) for low-intensity or moderate-intensity statin therapy and 1·24 (1·06-1·44) for high-intensity statin therapy compared with placebo.

INTERPRETATION

Statins cause a moderate dose-dependent increase in new diagnoses of diabetes that is consistent with a small upwards shift in glycaemia, with the majority of new diagnoses of diabetes occurring in people with baseline glycaemic markers that are close to the diagnostic threshold for diabetes. Importantly, however, any theoretical adverse effects of statins on cardiovascular risk that might arise from these small increases in glycaemia (or, indeed, from any other mechanism) are already accounted for in the overall reduction in cardiovascular risk that is seen with statin therapy in these trials. These findings should further inform clinical guidelines regarding clinical management of people taking statin therapy.

FUNDING

British Heart Foundation, UK Medical Research Council, and Australian National Health and Medical Research Council.

Long-term cardiovascular risks and the impact of statin treatment on socioeconomic inequalities: a microsimulation model

BACKGROUND

UK cardiovascular disease (CVD) incidence and mortality have declined in recent decades but socioeconomic inequalities persist.

AIM

To present a new CVD model, and project health outcomes and the impact of guideline-recommended statin treatment across quintiles of socioeconomic deprivation in the UK.

DESIGN AND SETTING

A lifetime microsimulation model was developed using 117 896 participants in 16 statin trials, 501 854 UK Biobank (UKB) participants, and quality-of-life data from national health surveys.

METHOD

A CVD microsimulation model was developed using risk equations for myocardial infarction, stroke, coronary revascularisation, cancer, and vascular and non-vascular death, estimated using trial data. The authors calibrated and further developed this model in the UKB cohort, including further characteristics and a diabetes risk equation, and validated the model in UKB and Whitehall II cohorts. The model was used to predict CVD incidence, life expectancy, quality-adjusted life years (QALYs), and the impact of UK guideline-recommended statin treatment across socioeconomic deprivation quintiles.

RESULTS

Age, sex, socioeconomic deprivation, smoking, hypertension, diabetes, and cardiovascular events were key CVD risk determinants. Model-predicted event rates corresponded well to observed rates across participant categories. The model projected strong gradients in remaining life expectancy, with 4-5-year (5-8 QALYs) gaps between the least and most socioeconomically deprived quintiles. Guideline-recommended statin treatment was projected to increase QALYs, with larger gains in quintiles of higher deprivation.

CONCLUSION

The study demonstrated the potential of guideline-recommended statin treatment to reduce socioeconomic inequalities. This CVD model is a novel resource for individualised long-term projections of health outcomes of CVD treatments.

Psychological Correlates of Mental Stress-induced Ischemia in the Laboratory: The Psychophysiological Investigation of Myocardial Ischemia (PIMI) Study

Participants consisted of 184 patients (160 males, 24 females) with positive angiograms or prior myocardial infarctions who displayed at least 1 mm of ST segment depression on a standardized treadmill test. Mean scores on the Reward Dependence subscale of the Tridimensional Personality Questionnaire were higher in patients displaying ischemia during mental stress. Patients who reported higher levels of irritability/anger in response to the Speech stressor were also more likely to display ischemia. However, this result was primarily a result of the females in the sample whose ratings of interest and irritability were associated with ischemia during the Speech task. Psychometric measures previously found in prospective studies to predict acute cardiac events were unrelated to mental stress-induced ischemia in the laboratory.

Pleiotropic effect of lovastatin, with and without cholestyramine, in the post coronary artery bypass graft (Post CABG) trial

This study evaluated patients in the Post Coronary Artery Bypass Graft (Post CABG) trial for evidence of statin pleiotropic effects in preventing atherosclerotic progression in saphenous vein grafts (SVGs). We studied 1,116 of the 1,351 patients in the Post CABG trial who were randomized to aggressive (low-density lipoprotein [LDL] cholesterol target <85 mg/dl) or moderate (target LDL cholesterol <140 mg/dl) lovastatin treatment and who had sufficient data available. The generalized estimating equation models, adjusting for important covariates, were applied to estimate the odds ratios (ORs) and probability of substantial atherosclerotic SVG progression (decrease in lumen diameter >or=0.6 mm) and the difference in minimum lumen diameter change between treatment groups. Aggressive lovastatin treatment compared with moderate treatment was associated with a significant decrease in risk of significant SVG atherosclerotic progression after adjustment for baseline cholesterol level, LDL cholesterol on treatment, high-density lipoprotein cholesterol, and triglyceride changes on treatment and other independent predictors (OR 0.68, 95% confidence interval 0.49 to 0.94, p = 0.019). Results were similar when the change or percent change from baseline of LDL cholesterol level on treatment was adjusted for rather than on-treatment LDL cholesterol and in the subset achieving a year-1 LDL cholesterol level from 90 to 135 mg/dl (OR 0.64, 95% confidence interval 0.42 to 0.98, p = 0.042). Mean decrease in minimum lumen diameter was also significantly smaller in the aggressive than the moderate treatment arm (-0.256 vs -0.343 mm, p = 0.042). In conclusion, aggressive versus moderate lovastatin treatment appeared therapeutic in slowing the atherosclerotic process in SVGs from Post CABG patients, independent of its greater LDL cholesterol-lowering effect.

Examination of the analytic quality of behavioral health randomized clinical trials

Adoption of evidence-based practice (EBP) policy has implications for clinicians and researchers alike. In fields that have already adopted EBP, evidence-based practice guidelines derive from systematic reviews of research evidence. Ultimately, such guidelines serve as tools used by practitioners. Systematic reviews of treatment efficacy and effectiveness reserve their strongest endorsements for treatments that are supported by high-quality randomized clinical trials (RCTs). It is unknown how well RCTs reported in behavioral science journals fare compared to quality standards set forth in fields that pioneered the evidence-based movement. We compared analytic quality features of all behavioral health RCTs (n = 73) published in three leading behavioral journals and two leading medical journals between January 2000 and July 2003. A behavioral health trial was operationalized as one employing a behavioral treatment modality to prevent or treat an acute or chronic physical disease or condition. Findings revealed areas of weakness in analytic aspects of the behavioral health RCTs reported in both sets of journals. Weaknesses were more pronounced in behavioral journals. The authors offer recommendations for improving the analytic quality of behavioral health RCTs to ensure that evidence about behavioral treatments is highly weighted in systematic reviews.

Lipoprotein lipase locus and progression of atherosclerosis in coronary-artery bypass grafts

PURPOSE

Our aim was to test whether polymorphisms in the lipoprotein lipase (LPL) gene were associated with the progression of atherosclerosis in grafts examined in the Post-Coronary Artery Bypass Graft Trial (Post-CABG Trial).

METHODS

843 subjects in the post-CABG trial were genotyped for the LPL-D9N, N291S, PvuII, (TTTA)n, and HindIII polymorphisms. Associations between genotype and angiographically measured progression of atherosclerosis in grafts, medical history, and family history were examined.

RESULTS

Greater progression of atherosclerosis was observed in subjects with LPL-HindIII 2/2 (56% versus 42% of those with other LPL HindIII genotypes, P = 0.025) and with LPL (TTTA)n 4/4 (63% versus 43% of those with other (TTTA)n genotypes, P = 0.020). Mantel-Haenszel analysis yielded an odds ratio of 1.84 for the effect of LPL HindIII 2/2 genotype on the progression of atherosclerosis in grafts (P = 0.015) and demonstrated that the effect of genotype on progression was of the same magnitude as, but independent of, the effect of drug treatment.

CONCLUSION

The LPL-HindIII 2/2 genotype is a marker for genetic variation in the 3'-end of LPL that acts as an independent risk factor for the progression of atherosclerosis in grafts examined in the Post-CABG Trial.

A summary of the findings from the Post-CABG trial

The Post-CABG trial was designed to assess the effects of 2 different lipid lowering strategies and low dose warfarin vs placebo (2 x 2 factorial) design on the progression of atherosclerosis in saphenous vein grafts. Atherosclerotic progression was determined by comparing baseline and follow-up angiograms (mean interval: 4.3 years) using quantitative angiography. Significant progression of disease in SVG's was reduced with the aggressive lipid lowering strategy compared to the moderate strategy; significant progression in SVG's was not altered by low dose warfarin. The beneficial effects on angiographic changes were demonstrated in multiple subgroups of participants in the trial. The composite clinical end point of death, MI, stroke, PTCA or repeat CABG was analyzed at the end of the trial and 3 years (extended follow-up) after closure of the angiographic trial. At the time of the extended follow-up the aggressive lipid strategy was associated with reduced clinical events; low dose warfarin was also associated with reduced clinical events.

Outcome and profile of women and men presenting with acute coronary syndromes: a report from TIMI IIIB. TIMI Investigators. Thrombolysis in Myocardial Infarction

OBJECTIVES

Women and men enrolled in the Thrombolysis in Myocardial Infarction (TIMI) IIIB trial of unstable angina and non-Q wave myocardial infarction (MI) were evaluated to determine gender differences in characteristics and outcome.

BACKGROUND

Coronary heart disease is the leading cause of death for women and men. However, the characteristics and outcome of women compared with men with unstable angina and non-Q wave MI have not been extensively studied.

METHODS

The characteristics, outcomes and proportion of 497 women and 976 men with unstable angina and non-Q wave MI at the time of enrollment were compared. When these proportions were noted to be significantly different, we compared them with the 7,731-patient TIMI IIIB Registry, which represents the non-trial, screened population with these syndromes at these centers.

RESULTS

For both coronary syndromes, women were older, were less frequently white, had a higher incidence of diabetes and hypertension and were receiving more cardiac medications. The 42-day rate of death and MI in TIMI IIIB was similar for women and men (7.4% vs. 7.5%). Coronary angiography revealed less severe coronary artery disease for women than for men, with absence of critical obstructions in 25% versus 16% and mean ejection fractions 62 +/- 12% versus 57 +/- 13% for women versus men (p < 0.01). Medical management failed in women as often as in men, and rates of cardiac catheterization and percutaneous transluminal coronary angioplasty or coronary artery bypass graft surgery were similar for women and men in the conservative strategy arm as well as in the invasive strategy arm. Women in the TIMI IIIB trial had proportionately more unstable angina than did men. The proportion of unstable angina and non-Q wave MI for women was similar in the trial and Registry. However, proportionately more men in the trial had non-Q wave MI than men in the Registry.

CONCLUSIONS

1) Women with each acute coronary syndrome are older than men and have more comorbidity. 2) The outcome with unstable angina and non-Q wave MI is related to severity of illness and not gender. 3) Mortality associated with revascularization for unstable angina and non-Q wave MI was similar for women and men. 4) The proportion of women and men enrolled with each acute coronary syndrome is different. These rates reflect both the prevalence of disease and selection bias owing to trial eligibility criteria and other identified factors.

Relation between clinical, angiographic and ischemic findings at baseline and ischemia-related adverse outcomes at 1 year in the Asymptomatic Cardiac Ischemia Pilot study. ACIP Study Group

OBJECTIVES

We attempted to investigate the relation between patient characteristics and adverse outcome in patients with ischemia and clinically stable coronary artery disease (CAD).

BACKGROUND

Evidence suggests that cardiac ischemia, detected by exercise stress testing (ETT) and ambulatory electrocardiographic (AECG) monitoring during daily living, identifies a subgroup of patients at increased risk for adverse outcome, but the relation between these ischemia findings and clinical and angiographic characteristics is largely unknown.

METHODS

We examined the relation between clinical, angiographic and ischemia characteristics at entry with adverse outcome observed at 1 year in the 558 patients enrolled in the Asymptomatic Cardiac Ischemia Pilot (ACIP) study.

RESULTS

By the 12-month visit 13.1% of patients had an ischemia-related adverse clinical outcome that included death, nonfatal myocardial infarction or an ischemia-related hospital admission. Multivariate analysis identified only the number of AECG ischemic episodes at entry (odds ratio [OR] 1.06, 99% confidence interval [CI] 1.01 to 1.12, p = 0.002) as an independent predictor of outcome. Assignment to revascularization (as opposed to an initial medical treatment strategy) showed a trend (OR 0.56, 99% CI 0.26 to 1.2, p = 0.05). None of the other baseline clinical, exercise or angiographic variables examined provided additional information relative to adverse outcome.

CONCLUSIONS

Determinants of adverse outcome, among clinically stable patients with CAD and ischemia induced by stress and daily life were magnitude of AECG ischemia before treatment and, possibly, initial treatment assignment. Among the many other characteristics examined, including age, symptom status and angiographic and exercise variables, none contributed additional independent prognostic information. These two simple variables, which may be modifiable, need further study in a larger trial.

Left ventricular, peripheral vascular, and neurohumoral responses to mental stress in normal middle-aged men and women. Reference Group for the Psychophysiological Investigations of Myocardial Ischemia (PIMI) Study

BACKGROUND

The normal cardiovascular response to mental stress in middle-aged and older people has not been well characterized.

METHODS AND RESULTS

We studied 29 individuals 45 to 73 years old (15 women, 14 men) who had no coronary risk factors, no history of coronary artery disease, and a negative exercise test. Left ventricular (LV) volumes and global and regional function were assessed by radionuclide ventriculography at rest and during two 5-minute standardized mental stress tasks (simulated public speaking and the Stroop Color-Word Test), administered in random order. A substantial sympathetic response occurred with both mental stress tests, characterized by increases in blood pressure, heart rate, rate-pressure product, cardiac index, and stroke work index and rises in plasma levels of epinephrine and norepinephrine but not beta-endorphin or cortisol. Despite this sympathetic response, LV volume increased and ejection fraction (EF) decreased secondary to an increase in afterload. The change in EF during mental stress-varied among individuals but was associated positively with changes in LV contractility and negatively with baseline EF and changes in afterload. EF decreased > 5% during mental stress in 12 individuals and > 8% in 5; 3 developed regional wall motion abnormalities.

CONCLUSIONS

Mental stress in the laboratory results in a substantial sympathetic response in normal middle-aged and older men and women, but EF commonly falls because of a concomitant rise in afterload. These results provide essential age- and sex-matched reference data for studies of mental stress-induced ischemia in patients with coronary artery disease.

Factors limiting the enrollment of women in a randomized coronary artery disease trial. The Asymptomatic Cardiac Ischemia Pilot Study (ACIP) Investigators

BACKGROUND AND HYPOTHESIS

Although it is recognized that women have been underrepresented in clinical trials of cardiovascular disease, the reasons for their limited enrollment have not been elucidated.

METHODS

A prospective tracking system was established in the Asymptomatic Cardiac Ischemia Pilot study (ACIP) to monitor recruitment and identify protocol issues that interfered with the recruitment of women. Patients with stress test evidence for ischemia during the course of routine clinical care were screened for asymptomatic ischemia with an ambulatory electrocardiogram (ECG).

RESULTS

Those with at least one episode of asymptomatic ischemia and angiographic evidence of coronary artery disease suited for revascularization could be randomized. Women comprised only 17% of the 1,820 patients screened for asymptomatic ischemia, and only 14% of the 558 patients randomized. The limited number of women screened for ischemia was largely due to the limited number of women (25% of all patients) found to have test evidence for ischemia or coronary artery disease suited for revascularization during the course of routine clinical care. Once patients were identified as having ischemia on stress test and ambulatory ECG, the major difference in eligibility was the difference in disqualifying angiograms, occurring 21/2 times as frequently in women as in men (p < 0.001).

CONCLUSION

The percentage of women recruited was lower than the prevalence of ischemic heart disease in the general population because at participating centers (1) women were found to have ischemia less often than men during the course of routine clinical care, and (2) screening tests for ischemia were less predictive of protocol-defined coronary disease in women than in men.

Individual risk assessment for intracranial haemorrhage during thrombolytic therapy

Thrombolytic therapy improves outcome in patients with myocardial infarction but is associated with an increased risk of intracranial haemorrhage. For some patients, this risk may outweigh the potential benefits of thrombolytic treatment. Using data from other studies, we developed a model for the assessment of an individual's risk of intracranial haemorrhage during thrombolysis. Data were available from 150 patients with documented intracranial haemorrhage and 294 matched controls. 49 patients with intracranial haemorrhage and 122 controls had been treated with streptokinase, whereas 88 cases and 148 controls had received alteplase. By multivariate analysis, four factors were identified as independent predictors of intracranial haemorrhage; age over 65 years (odds ratio 2.2 [95% Cl 1.4-3.5]), body weight below 70 kg (2.1 [1.3-3.2]), hypertension on hospital admission (2.0 [1.2-3.2]), and administration of alteplase (1.6 [1.0-2.5]). If the overall incidence of intracranial haemorrhage is assumed to be 0.75%, patients without risk factors who receive streptokinase have a 0.26% probability of intracranial haemorrhage. The risk is 0.96%, 1.32%, and 2.17% in patients with one, two, or three risk factors, respectively. We present a model for individual risk assessment that can be used easily in clinical practice.

One-year results of the Thrombolysis in Myocardial Infarction investigation (TIMI) Phase II Trial

BACKGROUND

The Thrombolysis in Myocardial Infarction (TIMI) Phase II Trial randomized 3,339 patients to either an invasive (INV, n = 1,681) or a conservative (CON, n = 1,658) strategy after intravenous recombinant tissue-type plasminogen activator (rt-PA) for acute myocardial infarction.

METHODS AND RESULTS

The patients assigned to the INV strategy routinely underwent cardiac catheterization, and when anatomically appropriate, percutaneous transluminal coronary angioplasty (PTCA) or coronary artery bypass grafting 18-48 hours after infarction. CON patients had these procedures only in response to the occurrence of spontaneous or provoked ischemia. One-year follow-up data are available in 3,316 patients (99.3%). The primary trial end point, death and nonfatal reinfarction, occurred in 14.7% of INV patients and in 15.2% of CON patients (p = NS). When analyzed individually, there was no difference (p = NS) in death (INV, 6.9%; CON, 7.4%) or recurrent infarction (INV, 9.4%; CON, 9.8%) between the two groups. Anginal status at 1 year was also similar. Cardiac catheterization and PTCA were performed more often in INV (98.0% and 61.2%, respectively) compared with CON (45.2% and 20.5%, respectively) patients. At 1 year, the cumulative number of patients who underwent coronary bypass surgery (INV, 17.5%; CON, 17.3%) was similar in the two groups.

CONCLUSIONS

The INV and CON strategies resulted in similar favorable outcomes at 1 year of follow-up. In particular, the rates of mortality and reinfarction were not different and were impressively low in both groups. One possible advantage of the INV strategy was detected in subgroup analyses. In patients with a history of myocardial infarction, the data are suggestive that 1-year mortality was lower in INV patients (10.3%) than in CON patients (17.0%) (p = 0.03).

Assessment of global and regional left ventricular performance at rest and during exercise after thrombolytic therapy for acute myocardial infarction: results of the Thrombolysis in Myocardial Infarction (TIMI) II Study

Global and regional left ventricular performances were evaluated with equilibrium radionuclide angiocardiography in patients in the Thrombolysis in Myocardial Infarction (TIMI) II trial at the time of hospital discharge. Studies at rest were available in 1,162 (69%) of the invasive and 1,150 (69%) of the conservative strategy patients, and exercise studies in 1,133 (67%) of the invasive and 1,145 (69%) of the conservative patients. Repeat studies were performed at the time of 6-week follow-up. Global and regional ejection fraction at rest were both comparable in patients assigned to each of the treatment strategies. However, at the time of hospital discharge patients in the invasive strategy had normal exercise responses more frequently (29.7 vs 25.8% p = 0.01), greater peak exercise LV ejection fraction (54.8 +/- 13.8% vs 53.1 +/- 14.1%, p = 0.004), greater exercise--rest change in LV ejection fraction (3.7 +/- 6.7% vs 2.7 +/- 7.2%, p less than 0.001) and greater peak exercise infarct zone regional ejection fraction (53.2 +/- 31.1% vs 50.3 +/- 33.0%, p less than 0.001) than patients assigned to the conservative strategy. At 6-week follow-up these differences between treatment strategies were no longer evident. When data were restricted to those collected at comparable work loads, similar differences in hospital discharge exercise performance between invasive vs conservative strategy patients were observed. Thus, there is a small transient difference in exercise global and regional LV performance associated with an invasive as opposed to conservative strategy after thrombolytic therapy. These differences are noted at the time of hospital discharge but not at 6 weeks, and are unlikely to confer clinical benefit.

Plasmapheresis and subsequent pulse cyclophosphamide versus pulse cyclophosphamide alone in severe lupus: design of the LPSG trial. Lupus Plasmapheresis Study Group (LPSG)

A group of clinics are collaborating in the Lupus Plasmapheresis Study Group (LPSG) to investigate whether repeated plasmapheresis prior to pulse cyclophosphamide improves the therapeutical results in severe systemic lupus erythematosus (SLE). The underlying rationale is the hypothesis that plasmapheresis 1) eliminates pathogenic autoantibodies and immune complexes and 2) induces compensatory lymphocyte activation via feedback mechanisms between circulating antibodies and their respective clones ("antibody rebound"). It should be possible to utilize this enhanced activity for increased clonal deletion if pulse cyclophosphamide is applied shortly after plasmapheresis. Accordingly, in a randomized study, the LPSG will be comparing the repeated application of pulse cyclophosphamide alone with a treatment involving repeated plasmapheresis prior to the cyclophosphamide pulses in severe SLE. A third arm of the study will be gathering experience with a more intensified procedure. This overview summarizes the most important details of the planned study.

Quantitative radionuclide assessment of regional ventricular function after thrombolytic therapy for acute myocardial infarction: results of phase I Thrombolysis in Myocardial Infarction (TIMI) trial

In Thrombolysis in Myocardial Infarction (TIMI) Phase I,290 patients with acute myocardial infarction were randomized to either intravenous recombinant tissue-type plasminogen activator (rt-PA) or intravenous streptokinase. Two hundred twenty-nine patients had radionuclide ventriculograms at discharge for assessment of global and regional left ventricular ejection fraction. Among these 229 patients 185 had totally occluded infarct-related arteries, and angiographic reperfusion of the infarct-related artery occurred in 69% of patients treated with rt-PA and 28% of patients treated with streptokinase (p less than 0.001). Mean global left ventricular ejection fraction was not different for rt-PA-treated patients compared with streptokinase-treated patients (0.46 versus 0.45). However, the average regional ejection fraction of the regions subtended by the infarct-related artery showed a trend toward better average infarct region ejection fraction in patients treated with rt-PA than in patients treated with streptokinase (0.40 versus 0.36; 0.05 less than p less than 0.06). Analysis of data according to perfusion status of the infarct-related artery showed no difference in mean global left ventricular ejection fraction between patients with sustained versus nonsustained reperfusion (0.47 versus 0.44). However, there was better average regional ejection fraction of the region subtended by the infarct-related artery in patients with sustained reperfusion (0.40 versus 0.36; p less than 0.01). Thus, quantitation of regional left ventricular function by radionuclide techniques provides a noninvasive means for evaluating the effects of thrombolysis. This study suggests a direct relation between improvement of regional left ventricular function and the greater infarct-related artery patency rate achieved by rt-PA compared with streptokinase.

Six- and twelve-month follow-up of the phase I Thrombolysis in Myocardial Infarction (TIMI) trial

The Thrombolysis in Myocardial Infarction (TIMI) trial Phase I was designed to compare the efficacy and side effects of intravenous recombinant tissue-type plasminogen activator (rt-PA) and intravenous streptokinase (SK) in patients with acute myocardial infarction (AMI). As previously reported, rt-PA led to a reperfusion rate of 62% of totally occluded coronary arteries compared with 31% for SK (p less than 0.001). This study was not designed to determine if intravenous thrombolytic therapy decreases the mortality of AMI; however, the findings in these patients after 1 year of follow-up do permit certain insights into the impact of early reperfusion and reocclusion on the clinical course of patients with AMI. The mortality rate at 6 and 12 months was not significantly different in patients treated with rt-PA compared with SK (7.7% and 10.5% rt-PA vs 9.5% and 11.6% for SK). The frequency of recurrent AMI, coronary artery bypass grafting (CABG) and percutaneous transluminal coronary angioplasty (PTCA) was similar in the 2 treatment groups. There was no significant difference in 6- and 12-month mortality or in the rate of recurrent AMI in patients who received thrombolytic therapy before compared with after 4 hours of the onset of AMI symptoms. When the results were analyzed on the basis of the patency of the infarct-related artery, irrespective of thrombolytic agent used, for those patients with patent arteries 90 minutes after the initiation of therapy, there was a trend toward a lower 6-month (5.6% vs 12.5%) and 12-month mortality (8.1% vs 14.8%) (p = 0.07).(ABSTRACT TRUNCATED AT 250 WORDS)

Thrombolysis in Myocardial Infarction (TIMI) Trial--phase I: hemorrhagic manifestations and changes in plasma fibrinogen and the fibrinolytic system in patients treated with recombinant tissue plasminogen activator and streptokinase

Two hundred ninety patients with acute myocardial infarction were treated according to random assignment with an intravenous infusion of either 80 mg of recombinant tissue plasminogen activator (rt-PA) over 3 h or 1.5 million units of streptokinase over 1 h. Patients received an intravenous bolus of heparin (5,000 U [USP]) before pretreatment coronary angiography and a continuous infusion (1,000 U/h) starting 3 h later. The frequency of major and minor hemorrhagic events (33% rt-PA, 31% streptokinase) and associated transfusions (22% rt-PA, 20% streptokinase) were comparable in both groups. More than 70% of bleeding episodes in each group occurred at catheterization or vascular puncture sites. Precipitable fibrinogen levels, measured in plasma samples collected in the presence of a protease inhibitor (aprotinin), declined in rt-PA and streptokinase groups by averages of 26 and 57% at 3 h and by 33 and 58% at 5 h, respectively (rt-PA versus streptokinase, p less than 0.001). At 5 h the plasma plasminogen declined by 57% (rt-PA) and 82% (streptokinase) (p less than 0.001); plasma fibrin(ogen) degradation products were higher in streptokinase-treated patients (244 +/- 12 micrograms/ml, mean +/- SE) than in rt-PA-treated patients (97 +/- 9 micrograms/ml, p less than 0.001). At 27 h, plasma fibrinogen and plasminogen levels were lower and fibrin(ogen) degradation products higher than pretreatment levels in both groups. The frequency of hemorrhagic events was higher in patients with greater changes in plasma factors at 5 h; within treatment groups the levels of fibrin(ogen) degradation products correlated with bleeding complications (p less than 0.005). Thus, in the doses administered, rt-PA induces systemic fibrinogenolysis that is substantially less intense than that induced by streptokinase. The high frequency of bleeding encountered is related to the protocol used, including vigorous anticoagulation, arterial punctures and thrombolytic therapy. These findings emphasize the need for avoidance of invasive procedures and for meticulous care in the selection and management of patients subjected to thrombolytic therapy.

The Thrombolysis in Myocardial Infarction (TIMI) phase II pilot study: tissue plasminogen activator followed by percutaneous transluminal coronary angioplasty

The Thrombolysis in Myocardial Infarction (TIMI) Study Group is investigating whether percutaneous transluminal coronary angioplasty or intravenous beta-receptor blockers, or both, are useful adjuncts to recombinant tissue-type plasminogen activator (rt-PA) in the treatment of patients with acute myocardial infarction (TIMI II study). A total of 317 patients with acute myocardial infarction were treated an average of 2.7 hours after the onset of chest pain during the course of a nonrandomized pilot investigation with 150 mg of rt-PA given over 6 hours. This dose of rt-PA resulted in a high rate of infarct-related coronary artery patency (82 and 87% of patients catheterized an average of either 1 or 32 hours after entry, respectively) and a low 21 day mortality rate of 4.4%. Coronary angioplasty was performed successfully in greater than 90% of patients with appropriate anatomy and in greater than 50% of those treated with rt-PA. In 75 patients treated within 2 hours of the onset of chest pain only 2 (2.7%) were dead by 6 weeks. However, five cases of intracranial hemorrhage were noted, and the rt-PA dose was subsequently reduced to 100 mg given over 6 hours. The TIMI II design and the results of the TIMI II pilot study are discussed.

Thrombolysis in Myocardial Infarction (TIMI) Trial, Phase I: A comparison between intravenous tissue plasminogen activator and intravenous streptokinase. Clinical findings through hospital discharge

Intravenous administration of 80 mg of recombinant tissue plasminogen activator (rt-PA, 40, 20, and 20 mg in successive hours) and streptokinase (SK, 1.5 million units over 1 hr) was compared in a double-blind, randomized trial in 290 patients with evolving acute myocardial infarction. These patients entered the trial within 7 hr of the onset of symptoms and underwent baseline coronary arteriography before thrombolytic therapy was instituted. Ninety minutes after the start of thrombolytic therapy, occluded infarct-related arteries had opened in 62% of 113 patients in the rt-PA and 31% of 119 patients in the SK group (p less than .001). Twice as many occluded infarct-related arteries opened after rt-PA compared with SK at the time of each of seven angiograms obtained during the first 90 min after commencing thrombolytic therapy. Regardless of the time from onset of symptoms to treatment, more arteries were opened after rt-PA than SK. The reduction in circulating fibrinogen and plasminogen and the increase in circulating fibrin split products at 3 and 24 hr were significantly less in patients treated with rt-PA than in those treated with SK (p less than .001). The occurrence of bleeding events, administration of blood transfusions, and reocclusion of the infarct-related artery was comparable in the two groups. Thus, in patients with acute myocardial infarction, rt-PA elicited reperfusion in twice as many occluded infarct-related arteries as compared with SK at each of seven serial observations during the first 90 min after onset of treatment.

Intravenous recombinant tissue-type plasminogen activator in patients with acute myocardial infarction: a report from the NHLBI thrombolysis in myocardial infarction trial

The efficacy and safety of a 3 hr, 80 mg intravenous infusion of recombinant tissue-type plasminogen activator (rt-PA) were investigated in 47 patients with acute myocardial infarction. Coronary angiography, performed before the administration of rt-PA and for 90 min thereafter, demonstrated that 37 patients had total coronary occlusion before therapy. After 90 min of rt-PA (50 mg), reperfusion of the infarct-related artery was observed in 25 patients (68%). Continuous infusions of heparin for anticoagulation were administered for 8 to 10 days. Of 36 patients who underwent follow-up coronary cineangiography, 21 had initially presented with total occlusion and had experienced reperfusion at 90 min. Sustained perfusion of the infarct-related artery was observed in 14 (67%) of these 21 initially reperfused patients. Late angiography was performed in nine patients who initially demonstrated subtotal occlusion of the infarct-related artery; sustained perfusion was observed in eight (89%). Significant bleeding was observed in 15 patients (32%). A hematoma at the site of the acute catheterization accounted for most instances of significant bleeding (11/15, 73%). Administration of rt-PA resulted in a significant decline in fibrinogen and plasminogen while amounts of fibrin(ogen) degradation products rose. In no patient, however, did fibrinogen levels decline to less than 140 mg/dl. Thus, rt-PA, administered as a brief 80 mg intravenous infusion, is capable of restoring blood flow in a high proportion of patients with acute myocardial infarction due to total coronary obstruction. Declines in plasma fibrinogen and plasminogen are observed. If combined with heparin anticoagulation and invasive vascular procedures, significant bleeding is a common complication.(ABSTRACT TRUNCATED AT 250 WORDS)

High dose intravenous streptokinase for acute myocardial infarction: preliminary results of a multicenter trial

To assess the efficacy of intravenous streptokinase in patients with acute myocardial infarction, 40 patients (30 men and 10 women, mean age 54 years) with acute myocardial infarction were given 1.5 million U of streptokinase intravenously in 1 hour, and coronary arteriography was performed repeatedly to assess reperfusion. Streptokinase treatment was begun 270 +/- 86 (mean +/- SD) minutes after the onset of chest pain. Of the 40 patients, 34 had total or near total coronary occlusion before streptokinase administration. In 14 (41%) of these 34 patients, some reperfusion occurred during the 90 minutes after the administration of streptokinase, but in only 11 of the 14 was reperfusion present at 90 minutes. After streptokinase administration, all patients received heparin for 8 to 10 days; they were subsequently administered aspirin and dipyridamole. Clinical evidence of reocclusion during the first 24 hours of heparin therapy occurred in one patient. Thus, when given to patients with acute myocardial infarction and total coronary occlusion an average of 4 1/2 hours after the onset of chest pain, high dose intravenous streptokinase achieves reperfusion in only about 40% and results in sustained reperfusion in only about 30%.