Sacubitril/valsartan compared to ramipril in high-risk post-myocardial infarction patients stratified according to use of mineralocorticoid receptor antagonists: Insight from the PARADISE MI trial

AIM

It is unknown whether safety and clinical endpoints by use of sacubitril/valsartan (an angiotensin receptor-neprilysin inhibitor [ARNI]) are affected by mineralocorticoid receptor antagonists (MRA) in high-risk myocardial infarction (MI) patients. The aim of this study was to examine whether MRA modifies safety and clinical endpoints by use of sacubitril/valsartan in patients with a MI and left ventricular systolic dysfunction (LVSD) and/or pulmonary congestion.

METHODS AND RESULTS

Patients (n = 5661) included in the PARADISE MI trial (Prospective ARNI vs. ACE Inhibitor Trial to Determine Superiority in Reducing Heart Failure Events After MI) were stratified according to MRA. Primary outcomes in this substudy were worsening heart failure or cardiovascular death. Safety was defined as symptomatic hypotension, hyperkalaemia >5.5 mmol/L, or permanent drug discontinuation. A total of 2338 patients (41%) were treated with MRA. Safety of ARNI compared to ramipril was not altered significantly by ± MRA, and both groups had similar increase in symptomatic hypotension with ARNI. In patients taking MRA, the risk of hyperkalaemia or permanent drug discontinuation was not significantly altered by ARNI (p > 0.05 for all comparisons). The effect of ARNI compared with ramipril was similar in those who were and were not taking MRA (hazard ratio [HR]MRA 0.96, 95% confidence interval [CI] 0.77-1.19 and HRMRA- 0.87, 95% CI 0.71-1.05, for the primary endpoint; p = 0.51 for interaction [Clinical Endpoint Committee adjudicated]); similar findings were observed if investigator-reported endpoints were evaluated (p = 0.61 for interaction).

CONCLUSIONS

Use of a MRA did not modify safety or clinical endpoints related to initiation of ARNI compared to ramipril in the post-MI setting in patients with LVSD and/or congestion.

Sex Differences in Clinical Characteristics and Outcomes After Myocardial Infarction With Low Ejection Fraction: Insights From PARADISE-MI

Background Studies demonstrated sex differences in outcomes following acute myocardial infarction, with women more likely to develop heart failure (HF). Sacubitril/valsartan has been shown to reduce cardiovascular death and HF hospitalizations in patients with HF with reduced ejection fraction. Methods and Results A total of 5661 patients (1363 women [24%]) with acute myocardial infarction complicated by reduced left ventricular ejection fraction (≤40%), pulmonary congestion, or both and ≥1 of 8 risk-augmenting factors were randomized to receive sacubitril/valsartan or ramipril. The primary outcome was cardiovascular death or incident HF. Baseline characteristics, clinical outcomes, and safety events were compared according to sex, a prespecified subgroup. Female participants were older and had more comorbidities. After multivariable adjustment, women and men were at similar risks for cardiovascular death or all-cause death. Women were more likely to have first HF hospitalization (hazard ratio [HR], 1.34 [95% CI, 1.05-1.70]; P=0.02) and total HF hospitalizations (HR, 1.39 [95% CI, 1.05-1.84]; P=0.02). Sex did not significantly modify the treatment effect of sacubitril/valsartan compared with ramipril on the primary outcome (P for interaction=0.11). Conclusions In contemporary patients who presented with reduced left ventricular ejection fraction, pulmonary congestion, or both, following acute myocardial infarction, women had a higher incidence of HF during follow-up. Sex did not modify the treatment effect of sacubitril/valsartan relative to ramipril. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT02924727.

DASH-HF Study: A Pragmatic Quality Improvement Randomized Implementation Trial for Patients With Heart Failure With Reduced Ejection Fraction

BACKGROUND

Heart failure is a prevailing diagnosis of hospitalization and readmission within 6 months, and nearly a quarter of these patients die within a year. Guideline-directed medication therapies reduce risk of mortality by 73% over 2 years; however, the implementation of these therapies to their target dose in clinical practice continues to be challenging. In 2020, the Veterans Affairs (VA) Health Care System developed a HF dashboard to monitor and improve outpatient HF management. The DASH-HF (Dashboard Activated Services and Telehealth for Heart Failure) study is a randomized, pragmatic clinical trial to evaluate proactive dashboard-directed telehealth clinics to improve the use and dosing of guideline-directed medication therapy for patients with heart failure with reduced ejection fraction not on optimal guideline-directed medication therapy within the VA.

METHODS

Three hundred veterans with heart failure with reduced ejection fraction met inclusion criteria with an optimization potential score (OPS) of 5 or less out of 10, representing nonoptimal guideline-directed medication therapy. The primary outcome was a composite score of guideline-directed medical therapy, the OPS, 6 months after the end of the intervention. Secondary outcomes included active prescriptions for each individual guideline-directed medical therapy class, HF-related hospitalizations, deaths, and clinician time per patient during the intervention clinics.

RESULTS

There was no significant difference between the intervention arm and usual care group in the primary outcome (OPS, 2.9; SD=2.1 versus OPS, 2.6, SD=2.1); adjusted mean difference 0.3 (95% CI, -0.1 to 0.7) or in the prespecified secondary outcomes for hospitalization and all-cause mortality for the intervention of proactive dashboard-based clinics.

CONCLUSIONS

A dashboard-based clinic intervention did not improve the OPS or secondary outcomes of hospitalization and all-cause mortality. There remains a larger opportunity to better target patients and provide more intensive follow-up to further evaluate the utility of proactive dashboard-based clinics for HF management and quality improvement.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT05001165.

Evidence-Based Cardiovascular Disease Medicines' Availability in Low-Cost Generic Drug Programs in the United States : A Cross-Sectional Study

BACKGROUND

Low-cost generic programs (LCGPs) that expand access to affordable cardiovascular disease (CVD) medicines can assist patients in achieving desired cardiovascular outcomes. It is important that LCGPs offer CVD medicines that promote evidence-based prescribing.

OBJECTIVE

To evaluate LCGPs' coverage of evidence-based CVD medications using a clinical framework that examines coverage of core treatments, coverage of options with the highest-quality evidence, and the variety of medication options and strengths that create choices and allow dosing titration.

DESIGN

Cross-sectional study.

SETTING

Publicly available LCGPs in March and April 2023 in the United States.

PARTICIPANTS

19 LCGPs.

MEASUREMENTS

Proportion of LCGPs that offered evidence-based CVD medicines within a clinical framework for 6 CVDs (atrial fibrillation, heart failure, hyperlipidemia, hypertension, post-acute coronary syndrome secondary prevention, and stable angina) according to 4 availability metrics (breadth, choice, high-quality evidence, and titratability).

RESULTS

The availability of CVD medication varied by program, drug, and CVD condition. Some programs had more breadth and choice of coverage for most CVDs (H-E-B, Kroger, Mark Cuban Cost Plus Drug Company, and Walmart), whereas many had more focused coverage and others markedly limited offerings. Nearly all LCGPs offered angiotensin-converting enzyme inhibitors, β-blockers, thiazides, and moderate-intensity statins, but availability was low for higher-cost or lower-use generics (antiplatelets and antiarrhythmics). Core pharmacotherapy coverage and choices were limited for atrial fibrillation and heart failure but widely available for hypertension and hyperlipidemia.

LIMITATION

In-depth cost analysis was not investigated.

CONCLUSION

Coverage of evidence-based medications for the 6 CVDs investigated varied by LCGP and condition. Because high availability of core CVD pharmacotherapy can enhance optimal disease state management, LCGPs should identify existing limitations in their coverage and continuously revise their formularies to improve the comprehensiveness of CVD medication coverage.

PRIMARY FUNDING SOURCE

None.

The design of the Dashboard Activated Services and Telehealth for Heart Failure (DASH-HF) study: A pragmatic quality improvement randomized implementation trial for patients with heart failure with reduced ejection fraction

BACKGROUND

Gaps in the receipt and dosing of guideline-directed medical therapy (GDMT) persist for patients with heart failure with reduced ejection fraction (HFrEF) [1]. In 2020, the Veterans Affairs (VA) developed a heart failure (HF) specific population dashboard to monitor care quality and performance on standard HFrEF performance measures [2].

METHODS

The Dashboard Activated Services and Telehealth for HF (DASH-HF) study is a pragmatic randomized quality improvement study designed to evaluate the utility of proactive population management clinics using the VA's HF dashboard to optimize GDMT for patients with HFrEF. Panel management telemedicine clinics incorporated multidisciplinary clinicians to perform chart review and impromptu telephone encounters to evaluate current HFrEF management and opportunities to optimize GDMT. The study will evaluate the efficacy of proactive panel management to usual care at 6 months as quantified by the GDMT optimization potential score. Secondary outcomes include hospitalizations, mortality, and clinician time per intervention. The study completed enrollment and randomization of 300 participants. The intervention was performed from September to December 2021.

CONCLUSION

DASH-HF will contribute to the literature by evaluating use of the existing VA dashboard to identify HF patients with the lowest adherence to GDMT and proactively target this group for the intervention.

REGISTRATION

https://clinicaltrials.gov/. Unique identifier: NCT05001165.

Angiotensin Receptor-Neprilysin Inhibition in Acute Myocardial Infarction

BACKGROUND

In patients with symptomatic heart failure, sacubitril-valsartan has been found to reduce the risk of hospitalization and death from cardiovascular causes more effectively than an angiotensin-converting-enzyme inhibitor. Trials comparing the effects of these drugs in patients with acute myocardial infarction have been lacking.

METHODS

We randomly assigned patients with myocardial infarction complicated by a reduced left ventricular ejection fraction, pulmonary congestion, or both to receive either sacubitril-valsartan (97 mg of sacubitril and 103 mg of valsartan twice daily) or ramipril (5 mg twice daily) in addition to recommended therapy. The primary outcome was death from cardiovascular causes or incident heart failure (outpatient symptomatic heart failure or heart failure leading to hospitalization), whichever occurred first.

RESULTS

A total of 5661 patients underwent randomization; 2830 were assigned to receive sacubitril-valsartan and 2831 to receive ramipril. Over a median of 22 months, a primary-outcome event occurred in 338 patients (11.9%) in the sacubitril-valsartan group and in 373 patients (13.2%) in the ramipril group (hazard ratio, 0.90; 95% confidence interval [CI], 0.78 to 1.04; P = 0.17). Death from cardiovascular causes or hospitalization for heart failure occurred in 308 patients (10.9%) in the sacubitril-valsartan group and in 335 patients (11.8%) in the ramipril group (hazard ratio, 0.91; 95% CI, 0.78 to 1.07); death from cardiovascular causes in 168 (5.9%) and 191 (6.7%), respectively (hazard ratio, 0.87; 95% CI, 0.71 to 1.08); and death from any cause in 213 (7.5%) and 242 (8.5%), respectively (hazard ratio, 0.88; 95% CI, 0.73 to 1.05). Treatment was discontinued because of an adverse event in 357 patients (12.6%) in the sacubitril-valsartan group and 379 patients (13.4%) in the ramipril group.

CONCLUSIONS

Sacubitril-valsartan was not associated with a significantly lower incidence of death from cardiovascular causes or incident heart failure than ramipril among patients with acute myocardial infarction. (Funded by Novartis; PARADISE-MI ClinicalTrials.gov number, NCT02924727.).

Prior Authorization, Copayments, and Utilization of Sacubitril/Valsartan in Medicare and Commercial Plans in Patients With Heart Failure With Reduced Ejection Fraction

BACKGROUND

Slow uptake of sacubitril/valsartan in patients with heart failure with reduced ejection fraction has been reported, which may negatively impact clinical outcomes. We characterized prior authorization (PA) burden, prescription copayment, and utilization of sacubitril/valsartan by insurance plan type to identify potential barriers to its use.

METHODS

We conducted a national population-level, cross-sectional study using PA data from an insurance coverage website accessed in March 2019 and IQVIA National Prescription Audit data from August 2018 to July 2019. Primary outcomes were proportion of plans requiring PA, frequency of specific PA criteria, number of sacubitril/valsartan prescriptions, and copayments per insurance plan type.

RESULTS

Overall, 48.1% (1394/2896) of insurance plans required PA for sacubitril/valsartan. Fewer Medicare (27.7%) than commercial (57.2%) plans required PA (P<0.001). For both plan types, the most frequently required PA criteria were ejection fraction (71.6%, 90.9%) and New York Heart Association class (60.4%, 90.8%) for Medicare and commercial plans, respectively. Copayment amounts varied by plan type, with more sacubitril/valsartan prescriptions for commercial plans not requiring a patient copayment (32.4%) compared with Medicare plans (19.3%; P<0.001). There were 814 437 sacubitril/valsartan prescriptions for Medicare and 822 292 for commercial plans dispensed from August 2018 to July 2019. Based on estimated heart failure with reduced ejection fraction populations for each plan type, 4-fold more sacubitril/valsartan prescriptions were dispensed in commercial than in Medicare plans (820 versus 215 prescriptions/1000 individuals in the heart failure with reduced ejection fraction population). The estimated proportion of heart failure with reduced ejection fraction patients prescribed sacubitril/valsartan was 3.6% (1.5%-6.8%) for Medicare and 13.7% (4.9%-31.8%) for commercial plan populations.

CONCLUSIONS

Despite commercial plans having greater PA requirements than Medicare, population-adjusted use of sacubitril/valsartan was higher in commercial plans. Given that commercial plans had more prescriptions with low copayments than Medicare, copayment policies may be more influential on sacubitril/valsartan use than its PA policies. Low sacubitril/valsartan use in both plan types highlights the multifactorial nature of medication underutilization that includes factors beyond the drug policies that we evaluated.

Impact of a Multidisciplinary Heart Failure Post-hospitalization Program on Heart Failure Readmission Rates

BACKGROUND

Specialized chronic heart failure (HF) clinics have demonstrated significant reductions in readmissions. Limited evidence is available regarding HF clinics in the immediate post-discharge period.

OBJECTIVE

To evaluate the effect of a multidisciplinary HF clinic on 90-day readmission rates and all-cause mortality in those recently discharged from a HF hospitalization.

METHODS

In this retrospective cohort study, patients discharged with a primary HF diagnosis who attended the HF postdischarge clinic in 2010-2012 were compared with controls from 2009. During 6 clinic visits, patients were seen by a physician assistant, clinical pharmacist specialist, and case manager, with care overseen by a cardiologist. The program focused on optimizing therapy, identifying HF etiology/precipitating factors, medication titration, education, and medication adherence. The primary outcome was 90-day HF readmission. A multivariate Cox proportional hazards model was used to compare outcomes.

RESULTS

Among the 277 patients (144 clinic, 133 control) in the study, 7.6% of patients in the clinic and 23.3% of patients in the control group were readmitted for HF within 90 days (aHR (adjusted hazard ratio) = 0.17; 95% CI = 0.07-0.41; P < 0.001; ARR (absolute risk reduction) = 15.7%; NNT (number needed to treat) = 7). Clinic patients had lower 90-day time-to-first HF readmission or all-cause mortality (9.0% vs 28.6%; aHR = 0.28; 95% CI = 0.06-0.31; P < 0.001; ARR = 19.6%; NNT = 6).

CONCLUSIONS

The multidisciplinary HF posthospitalization outpatient program was associated with a significant reduction in 90-day HF readmissions in patients who were recently discharged from a HF hospitalization.

Rates and predictors of ACE inhibitor discontinuation subsequent to elevated serum creatinine: a retrospective cohort study

OBJECTIVES

ACE inhibitors (ACEI) are underutilised despite cardiovascular benefits, in part due to concerns of known transient elevations in serum creatinine (SCr) after initiation. Our objectives were to evaluate rates and predictors of ACEI discontinuation after SCr elevation post-ACEI initiation since limited data are available that examine this issue.

SETTING

Primary and tertiary Veterans healthcare system in Los Angeles, California, USA PARTICIPANTS: 3039 outpatients initiating an ACEI with a SCr measured within 6 months prior to and approximately 3 months after initiating an ACEI. Patients were divided into three groups (SCr <1.5, 1.5–2 and >2).

PRIMARY AND SECONDARY OUTCOME MEASURES

Rates and factors associated with ACEI discontinuation subsequent to SCr elevation after ACEI initiation and for patients with baseline SCr >2 mg/dL, the change in SCr associated with chronic use. Predictors were identified using multivariate logistic regression modelling.

RESULTS

At 3 months follow-up, for those with an increase in SCr, the mean increase post-ACEI initiation was 26%, ranging from −0.01 mg/dL to 0.42 mg/dL varying according to a level of baseline renal function. ACEI discontinuation was higher in patients with elevated baseline SCr (19/165, 11.5%) compared with those with SCr <1.5 (135/2497, 5.4%), and those with SCr 1.5–2.0 (28/377, 7.4%). Male patients, and those with heart failure were less likely to discontinue ACEI after an elevation of SCr post-ACEI initiation, while those taking non-steroidal anti-inflammatory drugs, diuretics and β-blockers were more likely to discontinue ACEI.

CONCLUSIONS

SCr increases <30% on average within 3 months of ACEI initiation, with subsequent discontinuation rates varying by baseline SCr. Elevation in SCr was not associated with ACEI discontinuation rates. In patients with SCr >2 mg/dL at baseline, despite an acute increase in SCr after ACEI initiation, chronic ACEI use was associated with a decrease in SCr in most patients.

Comparative testing of 5 nicotine systems: initial use and preferences

OBJECTIVE

To test initial reactions to 5 nicotine treatments (NRTs: 2 and 4 mg gum, inhaler, nasal spray, tablet) in a crossover study (n=41).

METHODS

Subjects used each medication on arising (1/2 day) and resumed smoking each afternoon. Subjects rated (individually) and ranked (comparatively) treatments on use, reinforcement, withdrawal, craving, and preferences.

RESULTS

Overall preferences: inhaler (49%), 4 mg gum (24%), 2 mg gum (10%), 2 mg tablet (10%), nasal spray (7%). Overall results were consistent with ratings and rankings of individual characteristics of drugs.

CONCLUSION

Subjects had varied reactions to NRTs that may affect initiation of cessation.

Dipyridamole-thallium/sestamibi before vascular surgery: a prospective blinded study in moderate-risk patients

PURPOSE

This study assessed in a prospective, blinded fashion whether a reversible defect on dipyridamole-thallium (DTHAL)/sestamibi (DMIBI) can predict adverse cardiac events after elective vascular surgery in patients with one or more clinical risk factors.

METHODS

Consecutive patients with one or more clinical risk factors underwent a preoperative blinded DTHAL/DMIBI. Patients with recent congestive heart failure (CHF) or myocardial infarction (MI) or severe or unstable angina were excluded.

RESULTS

Eighty patients (78% men; mean age, 65 years) completed the study. Diabetes mellitus was the most frequent clinical risk factor (73%), followed by age older than 70 years (41%), angina (29%), Q wave on electrocardiogram (26%), history of CHF (7%), and ventricular ectopy (3%). The results of DTHAL/DMIBI were normal in 36 patients (45%); a reversible plus or minus fixed defect was demonstrated in 28 patients (36%), and a fixed defect alone was demonstrated in 15 patients (19%). Nine adverse cardiac events (11%) occurred, including three cases of CHF, and one case each of unstable angina, Q wave MI, non-Q wave MI, and cardiac arrest (successfully resuscitated). Two cardiac deaths occurred (2% overall mortality), one after a Q wave MI and one after CHF and a non-Q wave MI. The cardiac event rate was 14% for reversible defect and 9.8% without reversible defect (P =.71). The cardiac event rate was 12.5% (one of eight cases) for two or more reversible defects, versus 11.1% (eight of 72 cases) for fewer than two reversible defects (P = 1.0). The sensitivity rate of two or more areas of redistribution was 11% (95% CI, 0.3%-48%), the specificity rate was 90%, and the positive and negative predictive values were 12.5% and 89%, respectively.

CONCLUSION

Our study demonstrated no association between reversible defects on DTHAL/DMIBI and adverse cardiac events in moderate-risk patients undergoing elective vascular surgery.

Antiarrhythmic agents for atrial fibrillation: focus on prolonging atrial repolarization

Atrial fibrillation (AF) has been the subject of considerable attention and intensive clinical research in recent years. Current opinion among physicians on the management of AF favors the restoration and maintenance of normal sinus rhythm. This has several potential benefits, including the alleviation of arrhythmia-associated symptoms, hemodynamic improvements, and possibly a reduced risk of thromboembolic events. After normal sinus rhythm has been restored, antiarrhythmic therapy is necessary to reduce the frequency of AF recurrence. In the selection of an antiarrhythmic agent, both efficacy and safety should be taken into consideration. Many antiarrhythmic agents have the capacity to provoke proarrhythmia, which may result in an increase in mortality. This is of particular concern with sodium-channel blockers in the context of patients with structural heart disease. Flecainide and propafenone are well tolerated and effective in maintaining sinus rhythm in patients without significant cardiac disease but with AF. Recent interest has focused on the use of class III antiarrhythmic agents, such as amiodarone, sotalol, dofetilide (recently approved), ibutilide (approved for chemical conversion of AF and atrial flutter), and azimilide (still to be approved) in patients with AF and structural heart disease. To date, amiodarone and sotalol still hold the greatest interest, and although controlled clinical trials with these agents have been few, a number are in progress and some have been recently completed. These agents are effective in maintaining normal sinus rhythm in patients with paroxysmal and persistent AF and are associated with a low incidence of proarrhythmia when used appropriately. Because of the relative paucity of placebo-controlled trials of antiarrhythmic agents in patients with AF, experience until recently has tended to dictate treatment decisions. Increasingly, selection of drug therapy is being based on a careful and individualized benefit-risk evaluation by means of controlled clinical trials, an approach that is likely to dominate the overall approach to the control of atrial fibrillation in the largest numbers of cases of the arrhythmia. Pharmacologic therapy is likely to be dominated by compounds that exert their predominant effect by prolonging atrial repolarization.

Trimetazidine-induced enhancement of myocardial glucose utilization in normal and ischemic myocardial tissue: an evaluation by positron emission tomography

Trimetazidine has an anti-ischemic effect in angina pectoris. This agent has no hemodynamic effects, and its benefit is presumed to be based on a metabolic mechanism of action. A group of 33 dogs undergoing openchest left anterior descending coronary artery (LAD) ligation causing prolonged ischemia were imaged with quantitative positron emission tomography (PET) using 2-[18F]fluoro-2-deoxy-D-glucose (18FDG) to measure regional glucose metabolic utilization (rGMU) and [11C]acetate to measure regional monoexponential washout rate constant (Kmono) for oxidative metabolism in nonrisk and ischemic-risk myocardium. A total of 20 dogs were pretreated with trimetazidine at low dose (n = 10, 1 mg/kg) and high dose (n = 10, 5 mg/kg) and compared with 13 control dogs. Microsphere-measured myocardial blood flow (mL/min/g) was measured preocclusion and repeated hourly after occlusion and expressed as a ratio of preocclusion myocardial blood flow to verify a stable level of ischemia during PET. No differences were seen in postocclusion ischemic risk/nonrisk myocardial blood flow between treatment groups (p = not significant [NS]). Preocclusion and hourly measurements of heart rate and blood pressure corrected for baseline revealed no difference in control dogs versus trimetazidine (low-dose and high-dose) groups (p = NS). 18FDG-derived rGMU (micromol/min/g) was increased in high-dose trimetazidine versus control dogs in nonrisk and ischemic risk groups, respectively (1.16+/-0.57 vs 0.51+/-0.38 and 0.43+/-0.29 vs 0.20+/-0.14; p <0.05). rGMU was increased proportionately in nonrisk and ischemic risk in all groups without significant differences when corrected for nonrisk rGMU (ischemic risk/nonrisk was 0.92+/-1.3 vs 0.64+/-0.66 vs 0.40+/-0.22 for control dogs, all trimetazidine and high-dose trimetazidine groups). Kmono (min(-1) was not altered in any group (nonrisk = 0.13+/-0.03 vs 0.13+/-0.03 vs 0.14+/-0.02 and ischemic risk = 0.18+/-0.05 vs 0.17+/-0.06 vs 0.16+/-0.06 for control dogs, all trimetazidine and high-dose trimetazidine groups, respectively; p = NS for nonrisk vs ischemic risk, between and within groups). Our data verify that trimetazidine does not alter hemodynamic porameters. It increases total glucose utilization (oxidative and glycolytic) in myocardium without preferential increase in ischemic tissue. Absence of change in total oxidative metabolism suggests increased glucose metabolism is predominantly glycolysis or an increase in glucose oxidation with similar decrease in fatty acid oxidation.

Efficacy of a nicotine inhaler in smoking cessation: a double-blind, placebo-controlled trial

A non-combustible nicotine inhaler, administered orally, has been developed for treatment of smokers. The inhaler allows weaning from nicotine while maintaining partial reinforcement of the ritual/sensory phenomena of smoking. Subjects were randomly assigned to active (n = 112) and placebo (n = 111) groups. Some behavioral intervention occurred as a function of participation. Strict abstinence (primary outcome criterion) was defined by CO < or = 8 ppm with no slips allowed at any time and cotinine values < or = 14 at 1 year. Survival analysis showed active inhaler was superior to placebo (p < 0.01). Active vs. placebo success rates were: 63% vs. 47% (day 3), 46% vs. 28% (week 1), 36% vs. 19% (week 2), 33% vs. 16% (week 3), 29% vs. 14% (week 6), 24% vs. 10% (3 months), 17% vs. 9% (6 months) and 13% vs. 8% (1 year). chi 2 analyses were significant through 3 months but not at 6 months (p < 0.08) or 1 year. Craving was relieved with active inhalers at day 3 and week 1. Subjects averaged six inhalers/day. Cotinine levels were 57-61% of smoking levels. Common side effects included throat/mouth irritation and coughing. Failure was predicted by early slips. The inhaler is clearly useful for short-term smoking cessation with potential for long-term efficacy. Extended access to the inhaler and relapse prevention training could improve success rates. Another promising approach would be to combine the inhaler with a nicotine patch.

Efficacy of a nicotine nasal spray in smoking cessation: a placebo-controlled, double-blind trial

Laboratory trials have demonstrated the efficacy of nicotine replacement in smoking cessation but absolute success rates are low. For many, nicotine gum is hard to use and transdermal nicotine is slow-acting and passive. A new, faster-acting nicotine nasal spray (NNS) can provide easily self-administered relief from cigarette withdrawal. The NNS was tested for safety and efficacy in smoking cessation. Two hundred and fifty-five smokers were randomized to NNS or a piperine placebo. Drug use was limited to 8-32 doses/day for 6 months. Subjects were tested while smoking and at post-cessation daily (week 1) with follow-up at weeks 2, 3, 6 and at 3 months, 6 months and 1 year. Continuous abstinence analyses (CO < or = 8 ppm; no slips) showed that NNS significantly enhanced success rates over placebo overall (p < 0.001) and at all test intervals. Differences at key intervals between active and placebo were: 63% vs. 40% (day 5), 51% vs. 30% (week 3), 43% vs. 20% (6 weeks), 34% vs. 13% (3 months), 25% vs. 10% (6 months) and 18% vs. 8% (1 year). Side effects were common but tolerable. Cotinine measures showed that replacement of nicotine approximated 30% of smoking levels. Hazard functions revealed relapse risks peaked at day 1, day 5 and 3 weeks for strict abstinence. It is concluded NNS is safe, efficacious and a viable alternative treatment for smoking cessation.

Value of metabolic imaging with positron emission tomography for evaluating prognosis in patients with coronary artery disease and left ventricular dysfunction

Patients with coronary artery disease (CAD) and severe left ventricular (LV) dysfunction have a high but variable annual mortality and some may benefit from myocardial revascularization. This study aimed to evaluate the prognostic value of positron emission tomography (PET), and its interrelation with the choice of medical therapy or revascularization for predicting survival and improvement in symptoms of heart failure in patients with CAD and LV dysfunction. Ninety-three consecutive patients with angiographic CAD and a mean LV ejection fraction of 0.25 who underwent cardiac PET studies for assessment of hypoperfused yet viable myocardium ("mismatch pattern") using N-13 ammonia and 18-F deoxyglucose were followed up for an average of 13.6 months. Fifty patients underwent medical treatment and 43 underwent revascularization. The Cox model analysis showed that the extent of mismatch had a negative effect (p = 0.02), whereas revascularization had a positive effect on survival (p = 0.04). The annual survival probability of patients with mismatch receiving medical therapy was lower than of those without mismatch (50 vs 92%, p = 0.007). Patients with mismatch who underwent revascularization had a higher survival rate than those treated medically (88 vs 50%, P = 0.03). The presence of mismatch also predicted improvement in heart failure symptoms after revascularization (p < 0.001). These results suggest that the presence of mismatch in patients with CAD and severe LV dysfunction is associated with poor annual survival with medical therapy. Revascularization in patients with PET mismatch appears to be associated with improved survival and heart failure symptoms.

Persistent twenty-four hour SPECT thallium-201 defects, plasma thallium-201 concentrations and PET metabolic viability

Previous studies have shown that defects on four hour thallium-201 redistribution images often exhibit late reversibility, suggesting that the thallium-201 scintigraphic assessment of myocardial viability might be influenced by delayed redistribution imaging. To assess tissue metabolic activity in segments with late thallium-201 defects, positron emission tomography (PET) with 13NH3 and 18FDG was performed in 26 coronary artery disease patients with left ventricular dysfunction undergoing twenty-four hour SPECT thallium-201 scintigraphy. In 13 patients, plasma thallium-201 levels were obtained at the time of SPECT study and integrated tracer concentrations were determined one, two, four and twenty-four hours following injection. On circumferential profile image analysis of the PET images, ischemia was defined by preserved glucose metabolism in hypoperfused myocardium while infarction was identified by concordant reductions in both perfusion and glucose metabolism. Nineteen patients had stress-redistribution SPECT studies and seven had rest-redistribution SPECT studies. Using a semi-quantitative scoring system, four experienced observers visually identified 100 fixed, 17 partially reversible and twelve completely reversible segmental SPECT thallium-201 defects. On PET, metabolic activity was identified in 51 (51%) fixed defects (21 PET ischemia, 30 PET normal) and nine (53%) partially reversible defects (five PET ischemia, four PET normal). Of the twelve completely reversible thallium-201 defects, six (50%) were normal on PET, five (42%) had PET ischemia and one (8%) had PET infarction. The relative number of fixed thallium-201 defects with metabolic activity on PET did not depend on whether a stress or rest thallium-201 study was performed, or on whether the plasma thallium-201 integral concentration was high or low relative to mean values at any time point. Despite delayed redistribution imaging, PET imaging identifies glucose metabolic activity, and therefore residual tissue viability, in the majority of fixed twenty-four hour thallium-201 defects.

Metabolism in non-ischemic myocardium during coronary artery occlusion and reperfusion

Blood flow and metabolism in non-ischemic myocardium were studied at baseline and during occlusion and reperfusion of the left anterior descending coronary artery in closed chest dogs using positron emission tomography. Myocardial blood flow (MBF) and oxygen consumption (MVO2) in non-ischemic tissue were each increased by 28% relative to the rate pressure product during occlusion, consistent with increased work to compensate for the dyskinetic segment. MVO2 in non-ischemic sectors remained elevated relative to the rate pressure product early (1-2 h) post-reperfusion, 21% above baseline, but subsequently normalized. When sectors with normal blood flow during occlusion were divided into sectors adjacent to and remote from the risk zone, MBF in the 2 sector groups was similar at all times, but metabolic differences were found. MVO2 was depressed by 15% in adjacent relative to remote sectors 1 day post-reperfusion, with a concomitant 62% increase in glucose metabolic rate; relative increases in glucose metabolism were found only when glucose metabolism was low in remote myocardium, suggesting a decreased suppressibility of glucose metabolism in adjacent myocardium. The kinetics of (1-11C] palmitate were also altered in adjacent sectors, consistent with a small increase in esterification relative to oxidation of long chain fatty acids. Thus, sectors adjacent to ischemic segments show metabolic changes similar to those seen in reversibly injured post-ischemic tissue, despite normal blood flow during occlusion.

Regional myocardial blood flow and glucose utilization in symptomatic patients with hypertrophic cardiomyopathy

BACKGROUND

Previous studies suggested the presence of myocardial ischemia in symptomatic patients with hypertrophic cardiomyopathy. Positron emission tomography, a technique that can identify metabolic consequences of ischemia in coronary artery disease, permits the noninvasive measurements of regional myocardial blood flow and glucose metabolism. This new quantitative imaging approach should therefore be suitable for detecting a possible enhancement of glucose utilization in myocardium of patients with hypertrophic cardiomyopathy and thus may help to elucidate the pathomechanism of ischemia in this disease.

METHODS AND RESULTS

In 13 symptomatic patients with hypertrophic cardiomyopathy, myocardial blood flow and glucose utilization were measured with intravenous N-13-ammonia and F-18 deoxyglucose at rest and, in four patients, again during supine bicycle exercise. At rest, blood flow was significantly lower in hypertrophied than in normal myocardium (0.78 +/- 0.19 versus 0.99 +/- 0.13 mL.min-1.g-1, p < 0.025), whereas rates of glucose utilization were similar (0.88 +/- 0.31 versus 0.87 +/- 0.35 mumol.min-1.g-1). With exercise, blood flow and glucose utilization failed to increase in hypertrophic and normal segments but became more heterogeneously distributed throughout the left ventricular myocardium. Blood flow-metabolism mismatches indicative of myocardial ischemia were noted in three patients at rest and in three of the four patients during exercise and were due to reduced flow in the presence of maintained glucose uptake. The discordance between flow and glucose metabolism in hypertrophied myocardium was significantly more prominent in younger than in older patients.

CONCLUSIONS

Normal or even elevated rates of glucose utilization and the presence of diminished blood flow in hypertrophied relative to normal myocardium suggest the presence of myocardial ischemia in symptomatic hypertrophic cardiomyopathy. The age dependence of blood flow metabolism disparity suggests differences in the underlying pathophysiology or severity of disease.

Blood flow-dependent uptake of indium-111 monoclonal antimyosin antibody in canine acute myocardial infarction

OBJECTIVES

The relation of myocardial blood flow and indium-111 (111In) antimyosin antibody uptake was studied by inducing myocardial infarction in 18 dogs, 8 with closed chest left anterior descending artery balloon occlusion for 3 h followed by reperfusion (group A) and 10 dogs with open chest left anterior descending artery ligation (without reperfusion, group B).

BACKGROUND

The relation of antimyosin uptake to myocardial injury has been documented. However, its relation to tracer delivery by myocardial blood flow has not been studied and has been assumed to be independent.

METHODS

Indium-111 antimyosin antibody, 2 mCi, was injected 20 min after reperfusion and 3 h after coronary artery ligation in groups A and B, respectively. Regional blood flows were determined by radiolabeled microspheres during occlusion and 24 h later in both groups. On day 2, dogs were killed after risk zone delineation with gentian violet. The heart was excised and stained with triphenyltetrazolium chloride solution and graded for increasing severity of tissue injury based on extent of staining. Microsphere activity and 111In antimyosin activity were measured in control tissue (grade 1), noninfarct tissue at risk (grade 2), mixed tissue (grade 3), infarct tissue (grade 4) and hemorrhagic infarct tissue (grade 5, present only in group A dogs). Count activity was normalized to that of the mean value in control tissue (grade 1) and expressed as a ratio of activity.

RESULTS

Indium-111 antimyosin activity was high in triphenyltetrazolium chloride grade 4 tissue in both groups but was attenuated in grade 4 tissue in group B dogs (10.6 +/- 5.1 vs. 5.0 +/- 4.5; p < 0.05 group A vs. group B), which had lower blood flow on day 2 (0.51 +/- 0.36 vs. 0.23 vs. 0.22; p < 0.01). Normalizing 111In antimyosin activity for blood flow on day 2 resulted in equivalent 111In antimyosin uptake for infarct tissue (32.6 +/- 21.6 vs. 36.6 +/- 29.8 for group A vs. group B; p = NS).

CONCLUSIONS

Thus, 111In antimyosin uptake is a specific marker of necrotic tissue with a high signal ratio in reperfused tissue. However, its uptake is dependent on residual blood flow in the infarct territory. Indium-111 antimyosin could potentially serve as a suitable tracer for infarct sizing if myocardial blood flow in the same region were factored simultaneously.

Positron emission tomography detects metabolic viability in myocardium with persistent 24-hour single-photon emission computed tomography 201Tl defects

BACKGROUND

Four-hour 201Tl redistribution images underestimate myocardial viability in patients with coronary artery disease (CAD). Because 4-hour defects often redistribute late, delayed imaging may enhance assessment of tissue viability. Myocardial metabolic activity was therefore assessed with positron emission tomography (PET) in 26 CAD patients with impaired ventricular function (ejection fraction, 32.1 +/- 13.9%) and 24-hour single-photon emission computed tomography (SPECT) 201Tl defects.

METHODS AND RESULTS

On circumferential profile analysis, PET ischemia was defined by preserved glucose metabolism in hypoperfused myocardium, and PET infarction was defined by concordant reductions in perfusion and metabolism. On 19 stress-redistribution and seven rest-redistribution SPECT studies, four observers visually scored 201Tl activity in eight segments on a scale from 0 (normal) to 3 (complete defect). Using an improvement in visual score > or = 0.75 to define redistribution, there were 100 fixed, 17 partially reversible, and 12 completely reversible defects. PET identified tissue metabolic activity in 51 (51%) segments with fixed defects (21 PET ischemia, 30 PET normal) and nine (53%) segments with partially reversible defects (five PET ischemia, four PET normal). When grouped by 24-hour score, the proportion of fixed defects with metabolic activity varied from 84% (scores < or = 1.4) to 15% (scores > 2.6). For partially reversible defects, only 53% with scores < 2.0 and one of two with scores > or = 2.0 were considered metabolically viable on PET. Of 12 completely reversible defects, six (50%) were normal, five (42%) had PET ischemia, and one (8%) had PET infarction. The proportion of fixed defects with metabolic activity did not depend on whether a rest or stress study was performed or on the change in visual score used to define 201Tl redistribution (0.25, 0.50, 0.75, and 1.00).

CONCLUSIONS

In CAD patients, PET identifies glucose metabolic activity in the majority of fixed 24-hour 201Tl defects. However, very severe (near-complete) 24-hour 201Tl defects are less likely to exhibit metabolic activity on PET imaging than are defects with less-pronounced reductions in segmental 201Tl activity.

Quantitative assessment of prolonged metabolic abnormalities in reperfused canine myocardium

BACKGROUND

Prolonged metabolic abnormalities have been demonstrated previously in postischemic myocardium, including relative increases in glucose uptake and abnormal fatty acid kinetics. However, quantitative metabolic information is limited, and the time course of changes in MVO2 in postischemic myocardium is unknown. To address these issues, chronically instrumented dogs were studied serially over 1 month after transient left anterior descending coronary artery (LAD) occlusion, using positron emission tomography.

METHODS AND RESULTS

Dynamic imaging protocols were used in conjunction with tracer kinetic models to quantify blood flow and metabolic rates. Myocardial sectors were defined as normal, predominantly reversibly injured, and infarct-containing, based on occlusion blood flow images and postmortem histochemistry. Myocardial blood flow and metabolism were homogeneous at baseline. During LAD occlusion for 3 hours, myocardial blood flow in reversibly injured and infarct-containing sectors (determined with 13NH3) was decreased to 46% and 23%, respectively, of blood flow in normal tissue. MVO2, determined with [1-11C]acetate, was decreased less than myocardial blood flow, consistent with increased oxygen extraction in the ischemic tissue. After reperfusion, blood flow normalized rapidly in reversibly injured tissue but remained depressed in infarct-containing sectors. Regional myocardial function, assessed by two-dimensional echocardiography, was severely depressed during occlusion and did not improve significantly until 1 week after reperfusion. MVO2 remained depressed after reperfusion in both reversibly injured and infarct-containing sectors, did not improve from occlusion levels until 1 week after reperfusion, and remained significantly depressed 1 month after reperfusion even in reversibly injured sectors; [1-11C]palmitate kinetics were also abnormal in postischemic tissue. As reported previously, glucose metabolic rates were increased relative to baseline in normal but not in postischemic tissue 3 hours after reperfusion. Subsequently, glucose metabolism tended to be higher in postischemic relative to normal myocardium.

CONCLUSIONS

The results demonstrate decreased oxidative metabolism in postischemic tissue, with concomitant abnormalities in palmitate kinetics and glucose metabolism. Oxidative metabolism and regional function demonstrated a parallel recovery with time.

Differentiating cardiomyopathy of coronary artery disease from nonischemic dilated cardiomyopathy utilizing positron emission tomography

To determine if imaging of blood flow (using N-13 ammonia) and glucose metabolism (using F-18 2-deoxyglucose) with positron emission tomography can distinguish cardiomyopathy of coronary artery disease from nonischemic dilated cardiomyopathy, 21 patients with severe left ventricular dysfunction who were evaluated for cardiac transplantation were studied. The origin of left ventricular dysfunction had been previously determined by coronary angiography to be ischemic (11 patients) or nonischemic (10 patients). Images were visually analyzed by three observers on a graded scale in seven left ventricular segments and revealed fewer defects in dilated cardiomyopathy compared with ischemic cardiomyopathy for N-13 ammonia (2.7 +/- 1.6 versus 5 +/- 0.6; p less than 0.03) and F-18 deoxyglucose (2.8 +/- 2.1 versus 4.6 +/- 1.1; p less than 0.03). An index incorporating extent and severity of defects revealed more homogeneity with fewer and less severe defects in subjects with nonischemic than in those with ischemic cardiomyopathy as assessed by imaging of flow (2.8 +/- 1.8 versus 9.2 +/- 3; p less than 0.001) and metabolism (3.8 +/- 3.3 versus 8.5 +/- 3.6; p less than 0.005). Diagnostic accuracy for distinguishing the two subgroups by visual image analysis was 85%. Using previously published circumferential count profile criteria, patients with dilated cardiomyopathy had fewer ischemic segments (0.4 +/- 0.8 versus 2.5 +/- 2 per patient; p less than 0.01) and infarcted segments (0.1 +/- 0.3 versus 2.4 +/- 1.4 per patient; p less than 0.001) than did patients with cardiomyopathy of coronary artery disease. The sensitivity for differentiating the two clinical subgroups using circumferential profile analysis was 100% and the specificity 80%. An index incorporating both number and severity of defects derived from circumferential profile analysis was significantly lower in subjects with dilated cardiomyopathy than in ischemic cardiomyopathy (0.3 +/- 0.8 versus 2.7 +/- 2.4; p less than 0.005). Thus, noninvasive positron emission tomographic imaging with N-13 ammonia and F-18 deoxyglucose is helpful in distinguishing patients with severe left ventricular dysfunction secondary to coronary artery disease from those with nonischemic cardiomyopathy, and a semiquantitative index such as circumferential profile analysis is superior to that of visual analysis alone.

Myocardial ischemia during cocaine withdrawal

STUDY OBJECTIVE

To determine the prevalence of myocardial ischemia in patients with cocaine addiction.

DESIGN

Myocardial ischemia in chronic cocaine users was detected by serial 24-hour electrocardiographic ambulatory (Holter) monitoring and exercise treadmill testing in chronic cocaine users. The Holter tapes were coded, scanned in a blinded manner, and mixed with the tapes of 42 normal volunteers and 119 patients with either stable or unstable angina.

SETTING

A 28-day inpatient, substance abuse treatment program followed by an outpatient treatment program.

PATIENTS

Twenty-one consecutive male chronic cocaine users.

MAIN RESULTS

Eight of the 21 patients with cocaine addiction had frequent episodes of ST elevation during Holter monitoring; these episodes occurred almost exclusively during the first 2 weeks of withdrawal. None of the volunteers and patients with stable angina and only 4% of the patients with unstable angina had episodes of ST elevation during Holter monitoring (cocaine users compared with volunteers, P = 0.0004). Of the 20 cocaine patients who had exercise treadmill testing, only 1 had a positive test for ischemia.

CONCLUSIONS

Cocaine users frequently develop silent myocardial ischemia manifesting as episodes of ST elevation during the first weeks of withdrawal. The underlying mechanisms for these changes remain unknown, but our observations support the hypothesis that coronary vasospasm plays an important role in cocaine-related ischemic syndromes.

Variability of indexes for myocardial ischemia: a comparison of exercise treadmill test, ambulatory electrocardiographic monitoring and symptoms of myocardial ischemia

Fifty-four patients with chronic stable angina were studied to determine and compare weekly variability of indexes for the detection of myocardial ischemia. All patients underwent three single-blind placebo periods, each lasting 1 week. An exercise treadmill test, 24 h ambulatory electrocardiographic (Holter) monitoring (analyzed blindly) and an accurate diary of anginal attacks and nitroglycerin use were obtained at the end of each placebo period. An unbalanced, completely random component of variance analysis was used to calculate a component for within subject variability and a component for among subject variability. The coefficient of variation and percent variation (within subjects) of onset of chest pain during exercise were 19% and 30%, respectively; the corresponding values were 28% and 33% for onset of 1 mm ST depression, 15% and 15% for exercise duration, 44% and 27% for number of ischemic episodes/24 h, 56% and 43% for anginal frequency and 55% and 27% for nitroglycerin consumption, respectively. With use of this statistical method and variation within subjects, the change in the value of each variable necessary to exceed those attributable to spontaneous variation was determined. The trade-off between repeated measurements and number of subjects, the sample size estimated for planning studies and the minimal sample size for using various designs were also determined. Although the data indicate that all indexes for myocardial ischemia, both during exercise and during daily activity, vary considerably, but the exercise variables have less variability and are more reproducible.(ABSTRACT TRUNCATED AT 250 WORDS)

Severity of silent myocardial ischemia on ambulatory electrocardiographic monitoring in patients with stable angina pectoris: relation to prognostic determinants during exercise stress testing and coronary angiography

The relation of silent ischemia in patients with stable angina to known predictors of severity of coronary disease on exercise stress testing and coronary angiography is poorly defined. This issue was therefore examined with use of Holter electrocardiographic (ECG) recordings, treadmill exercise tests and angiographic indexes in 102 patients (not taking antianginal therapy) and the results were compared with Holter and treadmill findings in 42 volunteers. A total of 159 ischemic episodes (90% silent) were identified during 2,503 h on Holter recording in 97 patients (mean duration per episode 22.7 +/- 147 min; range 1 to 234). Holter recordings had a 92% specificity and an 80% positive predictive value, but a sensitivity of only 37% and a negative predictive value of 27% for coronary disease. Sixty-three patients (Group I) had no ischemia on Holter recording, 22 (Group II) had a cumulative duration of 1 to 60 min/24 h and in 12 (Group III) ischemia exceeded 60 min/24 h. There was no significant correlation between cumulative ischemia duration on Holter recording and exercise duration or time to ST segment depression on treadmill exercise. In general, the greater the number of coronary vessels involved and the higher the proximal coronary artery stenosis score, the greater the likelihood of ischemia and the longer the cumulative ischemia duration on Holter recording. Irrespective of the severity of coronary disease, in about 25% of Holter recordings in each angiographic category there were no ischemic episodes.(ABSTRACT TRUNCATED AT 250 WORDS)