Baseline characteristics including blood and urine metal levels in the Trial to Assess Chelation Therapy 2 (TACT2)

BACKGROUND

The reduction in cardiovascular disease (CVD) events with edetate disodium (EDTA) in the Trial to Assess Chelation Therapy (TACT) suggested that chelation of toxic metals might provide novel opportunities to reduce CVD in patients with diabetes. Lead and cadmium are vasculotoxic metals chelated by EDTA. We present baseline characteristics for participants in TACT2, a randomized, double-masked, placebo-controlled trial designed as a replication of the TACT trial limited to patients with diabetes.

METHODS

TACT2 enrolled 1,000 participants with diabetes and prior myocardial infarction, age 50 years or older between September 2016 and December 2020. Among 959 participants with at least one infusion, 933 had blood and/or urine metals measured at the Centers for Diseases Control and Prevention using the same methodology as in the National Health and Nutrition Examination Survey (NHANES). We compared metal levels in TACT2 to a contemporaneous subset of NHANES participants with CVD, diabetes and other inclusion criteria similar to TACT2's participants.

RESULTS

At baseline, the median (interquartile range, IQR) age was 67 (60, 72) years, 27% were women, 78% reported white race, mean (SD) BMI was 32.7 (6.6) kg/m2, 4% reported type 1 diabetes, 46.8% were treated with insulin, 22.3% with GLP1-receptor agonists or SGLT-2 inhibitors, 90.2% with aspirin, warfarin or P2Y12 inhibitors, and 86.5% with statins. Blood lead was detectable in all participants; median (IQR) was 9.19 (6.30, 13.9) μg/L. Blood and urine cadmium were detectable in 97% and median (IQR) levels were 0.28 (0.18, 0.43) μg/L and 0.30 (0.18, 0.51) μg/g creatinine, respectively. Metal levels were largely similar to those in the contemporaneous NHANES subset.

CONCLUSIONS

TACT2 participants were characterized by high use of medication to treat CVD and diabetes and similar baseline metal levels as in the general US population. TACT2 will determine whether chelation therapy reduces the occurrence of subsequent CVD events in this high-risk population.

CLINICAL TRIALS REGISTRATION

ClinicalTrials.gov. Identifier: NCT02733185. https://clinicaltrials.gov/study/NCT02733185.

Contaminant Metals as Cardiovascular Risk Factors: A Scientific Statement From the American Heart Association

Exposure to environmental pollutants is linked to increased risk of cardiovascular disease. Beyond the extensive evidence for particulate air pollution, accumulating evidence supports that exposure to nonessential metals such as lead, cadmium, and arsenic is a significant contributor to cardiovascular disease worldwide. Humans are exposed to metals through air, water, soil, and food and extensive industrial and public use. Contaminant metals interfere with critical intracellular reactions and functions leading to oxidative stress and chronic inflammation that result in endothelial dysfunction, hypertension, epigenetic dysregulation, dyslipidemia, and changes in myocardial excitation and contractile function. Lead, cadmium, and arsenic have been linked to subclinical atherosclerosis, coronary artery stenosis, and calcification as well as to increased risk of ischemic heart disease and stroke, left ventricular hypertrophy and heart failure, and peripheral artery disease. Epidemiological studies show that exposure to lead, cadmium, or arsenic is associated with cardiovascular death mostly attributable to ischemic heart disease. Public health measures reducing metal exposure are associated with reductions in cardiovascular disease death. Populations of color and low socioeconomic means are more commonly exposed to metals and therefore at greater risk of metal-induced cardiovascular disease. Together with strengthening public health measures to prevent metal exposures, development of more sensitive and selective measurement modalities, clinical monitoring of metal exposures, and the development of metal chelation therapies could further diminish the burden of cardiovascular disease attributable to metal exposure.

Effect of Thromboprophylaxis on Clinical Outcomes After COVID-19 Hospitalization

BACKGROUND

Patients hospitalized with COVID-19 have an increased incidence of thromboembolism. The role of extended thromboprophylaxis after hospital discharge is unclear.

OBJECTIVE

To determine whether anticoagulation is superior to placebo in reducing death and thromboembolic complications among patients discharged after COVID-19 hospitalization.

DESIGN

Prospective, randomized, double-blind, placebo-controlled clinical trial. (ClinicalTrials.gov: NCT04650087).

SETTING

Done during 2021 to 2022 among 127 U.S. hospitals.

PARTICIPANTS

Adults aged 18 years or older hospitalized with COVID-19 for 48 hours or more and ready for discharge, excluding those with a requirement for, or contraindication to, anticoagulation.

INTERVENTION

2.5 mg of apixaban versus placebo twice daily for 30 days.

MEASUREMENTS

The primary efficacy end point was a 30-day composite of death, arterial thromboembolism, and venous thromboembolism. The primary safety end points were 30-day major bleeding and clinically relevant nonmajor bleeding.

RESULTS

Enrollment was terminated early, after 1217 participants were randomly assigned, because of a lower than anticipated event rate and a declining rate of COVID-19 hospitalizations. Median age was 54 years, 50.4% were women, 26.5% were Black, and 16.7% were Hispanic; 30.7% had a World Health Organization severity score of 5 or greater, and 11.0% had an International Medical Prevention Registry on Venous Thromboembolism risk prediction score of greater than 4. Incidence of the primary end point was 2.13% (95% CI, 1.14 to 3.62) in the apixaban group and 2.31% (CI, 1.27 to 3.84) in the placebo group. Major bleeding occurred in 2 (0.4%) and 1 (0.2%) and clinically relevant nonmajor bleeding occurred in 3 (0.6%) and 6 (1.1%) apixaban-treated and placebo-treated participants, respectively. By day 30, thirty-six (3.0%) participants were lost to follow-up, and 8.5% of apixaban and 11.9% of placebo participants permanently discontinued the study drug treatment.

LIMITATIONS

The introduction of SARS-CoV-2 vaccines decreased the risk for hospitalization and death. Study enrollment spanned the peaks of the Delta and Omicron variants in the United States, which influenced illness severity.

CONCLUSION

The incidence of death or thromboembolism was low in this cohort of patients discharged after hospitalization with COVID-19. Because of early enrollment termination, the results were imprecise and the study was inconclusive.

PRIMARY FUNDING SOURCE

National Institutes of Health.

Abstract P170: The Association of Urinary Cadmium and Zinc With Lower Extremity Amputations. Evidence From the Strong Heart Study

Background: Cadmium is a cardiotoxic divalent metal that accumulates in the liver and kidney. It resembles the essential metal zinc, replacing it in numerous enzymes and proteins. Zinc plays a major role in insulin function. Glucose dyshomeostasis increases the loss of zinc through the urine. Cadmium has been associated with peripheral artery disease and critical limb ischemia, conditions that lead to limb amputations. Chelation treatment with edetate disodium, an agent that facilitates the excretion of cadmium from the body, was beneficial for individuals with critical limb ischemia and diabetes in several small studies. This study evaluated the association of urinary levels of cadmium and zinc with amputations in a population with a high burden of diabetes from Arizona, Oklahoma, North Dakota and South Dakota.

Hypothesis: We hypothesize that urinary cadmium and zinc levels are related to prevalent amputations in the SHS cohort.

Methods: We included 2,724 participants from the Strong Heart Study, a population-based cohort study in 12 American Indian communities, recruited in 1989-1991 and followed for amputations through 1998-1999. Trained staff identified amputations of the lower extremity through visual examination at the baseline visit. We censored traumatic amputations. Baseline metal levels in spot urine samples were divided by urinary creatinine to account for urine dilution.

Results: Mean age was 56.4 years, 41.5% participants were male, and 42% had diabetes. We identified a total of 35 (1.3%) amputations of the lower extremities during the study period. Median urinary levels were 0.97 μg/g for cadmium and 0.56 mg/g for zinc. Higher levels of urinary cadmium and zinc were positively associated with the presence of amputations. The odds ratios of prevalent amputations for an IQR of cadmium and zinc distribution were 1.54 (1.00, 2.38) and 2.24 (1.48, 3.39), respectively, in models adjusted for sociodemographic, lifestyle (tobacco and alcohol intake), and other factors (BMI, hypertension and diabetes status, HDL and LDL-cholesterol, and estimated glomerular filtration rate). The associations remained after further adjustment for fasting plasma glucose levels. Urinary cadmium and zinc levels were positively correlated (r=0.24, P<0.001).

Conclusions: Urinary cadmium and zinc were positively associated with the presence of lower extremity amputations in American Indian adults with a high burden of diabetes. These results support the current evidence of cadmium as a cardiometabolic risk factor, and the potential role of impaired zinc metabolism, reflected as increased urinary zinc excretion, in vascular complications of diabetes.

Environment and cardiovascular health: causes, consequences and opportunities in prevention and treatment

The environment is a strong determinant of cardiovascular health. Environmental cardiology studies the contribution of environmental exposures with the aim of minimizing the harmful influences of pollution and promoting cardiovascular health through specific preventive or therapeutic strategies. The present review focuses on particulate matter and metals, which are the pollutants with the strongest level of scientific evidence, and includes possible interventions. Legislation, mitigation and control of pollutants in air, water and food, as well as environmental policies for heart-healthy spaces, are key measures for cardiovascular health. Individual strategies include the chelation of divalent metals such as lead and cadmium, metals that can only be removed from the body via chelation. The TACT (Trial to Assess Chelation Therapy, NCT00044213) clinical trial demonstrated cardiovascular benefit in patients with a previous myocardial infarction, especially in those with diabetes. Currently, the TACT2 trial (NCT02733185) is replicating the TACT results in people with diabetes. Data from the United States and Argentina have also shown the potential usefulness of chelation in severe peripheral arterial disease. More research and action in environmental cardiology could substantially help to improve the prevention and treatment of cardiovascular disease.

The trial to assess chelation therapy 2 (TACT2): Rationale and design

BACKGROUND

Intravenous edetate disodium-based infusions reduced cardiovascular events in a prior clinical trial. The Trial to Assess Chelation Therapy 2 (TACT2) will replicate the initial study design.

METHODS

TACT2 is an NIH-sponsored, randomized, 2x2 factorial, double masked, placebo-controlled, multicenter clinical trial testing 40 weekly infusions of a multi-component edetate disodium (disodium ethylenediamine tetra-acetic acid, or Na2EDTA)-based chelation solution and twice daily oral, high-dose multivitamin and mineral supplements in patients with diabetes and a prior myocardial infarction (MI). TACT2 completed enrollment of 1000 subjects in December 2020, and infusions in December 2021. Subjects are followed for 2.5 to 5 years. The primary endpoint is time to first occurrence of all-cause mortality, MI, stroke, coronary revascularization, or hospitalization for unstable angina. The trial has >;85% power to detect a 30% relative reduction in the primary endpoint. TACT2 also includes a Trace Metals and Biorepository Core Lab, to test whether benefits of treatment, if present, are due to chelation of lead and cadmium from patients. Design features of TACT2 were chosen to replicate selected features of the first TACT, which demonstrated a significant reduction in cardiovascular outcomes in the EDTA chelation arm compared with placebo among patients with a prior MI, with the largest effect in patients with diabetes.

RESULTS

Results are expected in 2024.

CONCLUSION

TACT2 may provide definitive evidence of the benefit of edetate disodiumbased chelation on cardiovascular outcomes, as well as the clinical importance of longitudinal changes in toxic metal levels of participants.

Chelation Therapy in Patients With Cardiovascular Disease: A Systematic Review

Background EDTA is an intravenous chelating agent with high affinity to divalent cations (lead, cadmium, and calcium) that may be beneficial in the treatment of cardiovascular disease (CVD). Although a large randomized clinical trial showed benefit, smaller studies were inconsistent. We conducted a systematic review of published studies to examine the effect of repeated EDTA on clinical outcomes in adults with CVD. Methods and Results We searched 3 databases (MEDLINE, Embase, and Cochrane) from database inception to October 2021 to identify all studies involving EDTA treatment in patients with CVD. Predetermined outcomes included mortality, disease severity, plasma biomarkers of disease chronicity, and quality of life. Twenty-four studies (4 randomized clinical trials, 15 prospective before/after studies, and 5 retrospective case series) assessed the use of repeated EDTA chelation treatment in patients with preexistent CVD. Of these, 17 studies (1 randomized clinical trial) found improvement in their respective outcomes following EDTA treatment. The largest improvements were observed in studies with high prevalence of participants with diabetes and/or severe occlusive arterial disease. A meta-analysis conducted with 4 studies reporting ankle-brachial index indicated an improvement of 0.08 (95% CI, 0.06-0.09) from baseline. Conclusions Overall, 17 studies suggested improved outcomes, 5 reported no statistically significant effect of treatment, and 2 reported no qualitative benefit. Repeated EDTA for CVD treatment may provide more benefit to patients with diabetes and severe peripheral arterial disease. Differences across infusion regimens, including dosage, solution components, and number of infusions, limit comparisons across studies. Additional research is necessary to confirm these findings and to evaluate the potential mediating role of metals. Registration URL: https://www.crd.york.ac.uk/; Unique identifier: CRD42020166505.

Low-Level Metal Contamination and Chelation in Cardiovascular Disease-A Ripe Area for Toxicology Research

Cardiovascular disease remains the leading cause of death worldwide. In spite of cardiovascular prevention, there is residual risk not explicable by traditional risk factors. Metal contamination even at levels previously considered safe in humans may be a potential risk factor for atherosclerosis. This review examines evidence that 2 metals, lead, and cadmium, demonstrate sufficient toxicological and epidemiologic evidence to attribute causality for atherosclerotic disease. Basic science suggests that both metals have profound adverse effects on the human cardiovascular system, resulting in endothelial dysfunction, an increase in inflammatory markers, and reactive oxygen species, all of which are proatherosclerotic. Epidemiological studies have shown both metals to have an association with cardiovascular disease, such as peripheral arterial disease, ischemic heart disease, and cardiovascular mortality. This review also examines edetate disodium-based chelation as a possible pharmacotherapy to reduce metal burden in patients with a history of cardiovascular disease and thus potentially reduce cardiovascular events.

VVI pacing with normal QRS duration and ventricular function: MOST trial findings relevant to leadless pacemakers

BACKGROUND

Leadless pacemakers (LPs) provide ventricular pacing without the risks associated with transvenous leads and device pockets. LPs are appealing for patients who need pacing, but do not need defibrillator or cardiac resynchronization therapy. Most implanted LPs provide right ventricular pacing without atrioventricular synchrony (VVIR mode). The Mode Selection Trial in Sinus Node Dysfunction (MOST) showed similar outcomes in patients randomized to dual-chamber (DDDR) versus ventricular pacing (VVIR). We compared outcomes by pacing mode in LP-eligible patients from MOST.

METHODS

Patients enrolled in the MOST study with an left ventricular ejection fraction (LVEF) >35%, QRS duration (QRSd) <120 ms and no history of ventricular arrhythmias or prior implantable cardioverter defibrillators were included (LP-eligible population). Cox proportional hazards models were used to test the association between pacing mode and death, stroke or heart failure (HF) hospitalization and atrial fibrillation (AF).

RESULTS

Of the 2010 patients enrolled in MOST, 1284 patients (64%) met inclusion criteria. Baseline characteristics were well balanced across included patients randomized to DDDR (N = 630) and VVIR (N = 654). Over 4 years of follow-up, there was no association between pacing mode and death, stroke or HF hospitalization (VVIR HR 1.28 [0.92-1.75]). VVIR pacing was associated with higher risk of AF (HR 1.32 [1.08-1.61], P = .007), particularly in patients with no history of AF (HR 2.38 [1.52-3.85], P < .001).

CONCLUSION

In patients without reduced LVEF or prolonged QRSd who would be eligible for LP, DDDR, and VVIR pacing demonstrated similar rates of death, stroke or HF hospitalization; however, VVIR pacing significantly increased the risk of AF development.

Possible differential benefits of edetate disodium in post-myocardial infarction patients with diabetes treated with different hypoglycemic strategies in the Trial to Assess Chelation Therapy (TACT)

BACKGROUND

The NIH-funded Trial to Assess Chelation Therapy (TACT) randomized 1708 stable patients age ≥50 who were ≥6 months post myocardial infarction to 40 infusions of an edetate disodium-based regimen or placebo. In 633 patients with diabetes, edetate disodium significantly reduced the primary composite endpoint of mortality, recurrent myocardial infarction, stroke, coronary revascularization, or hospitalization for angina (hazard ratio [HR] 0.59, 95% confidence interval [CI] 0.44-0.79, p < 0.001). The principal secondary endpoint of a composite of cardiovascular death, myocardial infarction, or stroke was also reduced (HR 0.60, 95% CI 0.39-0.91, p = 0.017). It is unknown if the treatment effect differs by diabetes therapy.

METHODS

We grouped the subset of 633 patients with diabetes according to glucose-lowering therapy at time of randomization. The log-rank test was used to compare active therapy versus placebo. All treatment comparisons were performed using 2-sided significance tests at the significance level of 0.05 and were as randomized. Relative risks were expressed as HR with associated 95% CI, calculated using the Cox proportional hazards model.

RESULTS

There were 162 (25.7%) patients treated with insulin; 301 (47.5%) with oral hypoglycemics only; and 170 (26.8%) receiving no pharmacologic treatment for diabetes. Patients on insulin reached the primary endpoint more frequently than patients on no pharmacologic treatment [61 (38%) vs 49 (29%) (HR 1.56, 95% CI 1.07-2.27, p = 0.022)] or oral hypoglycemics [61 (38%) vs 87 (29%) (HR 1.46, 1.05-2.03, p = 0.024)]. The primary endpoint occurred less frequently with edetate disodium based therapy versus placebo in patients on insulin [19 (26%) vs 42 (48%) (HR 0.42, 95% CI 0.25-0.74, log-rank p = 0.002)], marginally in patients on oral hypoglycemics [38 (25%) vs 49 (34%) (HR 0.66, 95% CI 0.43-1.01, log-rank p = 0.041)], and no significant difference in patients not treated with a pharmacologic therapy [23 (25%) vs 26 (34%) (HR 0.69, 95% CI 0.39-1.20, log-rank p = 0.225)]. The interaction between randomized intravenous treatment and type of diabetes therapy was not statistically significant (p = 0.203).

CONCLUSIONS

Edetate disodium treatment in stable, post-myocardial infarction patients with diabetes suggests that patients on insulin therapy at baseline may accrue the greatest benefit.

CLINICAL TRIAL REGISTRATION

clinicaltrials.gov identifier: http://clinicaltrials.gov/ct2/show/NCT00044213?term=TACT&rank=7 identifier Trial to Assess Chelation Therapy (TACT), NCT00044213.

Differential Outcomes With Edetate Disodium-Based Treatment Among Stable Post Anterior vs. Non-Anterior Myocardial Infarction Patients

BACKGROUND

The Trial to Assess Chelation Therapy (TACT) found that chelation therapy significantly reduced clinical events in patients with a history of myocardial infarction (MI). The initial report of TACT included the observation of an interaction between edetate disodium infusions and MI location, as well as diabetes. Thus, we examined in greater detail the effect of edetate disodium chelation therapy as a function of MI location and diabetes.

METHODS

Patients (n = 1708) at least 6 weeks post-MI and age ≥ 50 were randomized to receive 40 infusions of a 500 mL chelation solution or placebo (median follow-up 55 months). The effect of edetate disodium on the primary outcome (all-cause mortality, MI, stroke, hospitalization for angina, or coronary revascularization) was assessed as a function of MI location using log-rank test and Cox regression model, adjusting for other prognostic variables.

RESULTS

Among patients with post anterior MI (n = 674), chelation was associated with a lower risk of the primary endpoint (HR 0.63, 95% CI 0.47-0.86, p = 0.003) among anterior MI patients, but not in post non-anterior MI (n = 1034) patients (HR 0.96, 95% CI 0.77-1.20, p = 0.702) (p-for-interaction = 0.032). The point estimates for each component of the primary endpoint favored chelation therapy. The differing treatment effect in patients with post anterior vs. non-anterior MI was consistent among patients with or without diabetes and remained significant after adjusting for other prognostic variables (p < 0.01).

CONCLUSIONS

Edetate disodium infusions reduced the risk of cardiovascular events among patients with a prior anterior MI. Future studies should focus on replicating these results and understanding the mechanisms of benefit.

The effect of EDTA-based chelation on patients with diabetes and peripheral artery disease in the Trial to Assess Chelation Therapy (TACT)

OBJECTIVE

Approximately 1 in 7 US adults have diabetes; and over 60% of deaths in patients with diabetes have cardiac disease as a principal or contributing cause. Both coronary and peripheral artery disease (PAD) identify high-risk cohorts among patients with diabetes. We have previously demonstrated improved cardiovascular outcomes with edetate disodium-based chelation in post-MI patients with diabetes, enrolled in the Trial to Assess Chelation Therapy (TACT). In these analyses we further studied the effect size of patients with diabetes and severe disease in 2 vascular beds; coronaries, and lower extremity arteries. We questioned whether greater atherosclerotic burden would attenuate the observed beneficial effect of edetate disodium infusions.

RESEARCH DESIGN AND METHODS

The multicenter TACT used a double blind, placebo controlled, 2 × 2 factorial design with 1708 participants, randomly assigned to receive edetate disodium-based chelation, or placebo and high dose oral vitamins or placebo. There were 162 (9.5% of 1708) post-MI patients with a diagnosis of diabetes mellitus and PAD for this post hoc analysis. Patients received up to 40 double-blind intravenous infusions of edetate disodium-based chelation, or placebo. The composite primary endpoint of TACT consisted of death from any cause, myocardial infarction, stroke, coronary revascularization and hospitalization for angina.

RESULTS

The median age was 66 years, 15% female, 5% non-Caucasian, and BMI was 31. Insulin was used by 32% of patients. Active infusions significantly reduced the primary endpoint compared with placebo infusions (HR, 0.52; 95% CI, 0.30-0.92; P = 0.0069), with a 30% absolute risk reduction in the primary endpoint. There was a marked reduction in total mortality from 24% to 11%, although of borderline significance (P = 0.052).

CONCLUSION

Atherosclerotic disease in multiple vascular beds did not attenuate the beneficial effect of edetate disodium infusions in post MI patients with diabetes. Studies now in progress will prospectively test this post hoc finding.

Potential Role of Metal Chelation to Prevent the Cardiovascular Complications of Diabetes

CONTEXT

For decades, there has been epidemiologic evidence linking chronic toxic metal exposure with cardiovascular disease, suggesting a therapeutic role for metal chelation. Given the lack of compelling scientific evidence, however, the indications for metal chelation were never clearly defined. To determine the safety and efficacy of chelation therapy, the National Institutes of Health funded the Trial to Assess Chelation Therapy (TACT). TACT was the first double-blind, randomized, controlled trial to demonstrate an improvement in cardiovascular outcomes with edetate disodium therapy in patients with prior myocardial infarction. The therapeutic benefit was striking among the prespecified subgroup of patients with diabetes.

DESIGN

We review the published literature focusing on the atherogenic nature of diabetes, as well as available evidence from clinical trials, complete and in progress, of metal chelation with edetate disodium therapy in patients with diabetes.

RESULTS

The TACT results support the concept that ubiquitous toxic metals such as lead and cadmium may be modifiable risk factors for cardiovascular disease, particularly in patients with diabetes.

CONCLUSIONS

The purpose of this review is to discuss the potential mechanisms unifying the pathogenesis of atherogenic factors in diabetes with toxic metal exposure, and the potential role of metal chelation.

Chelation therapy to prevent diabetes-associated cardiovascular events

PURPOSE OF REVIEW

For over 60 years, chelation therapy with disodium ethylene diamine tetraacetic acid (EDTA, edetate) had been used for the treatment of cardiovascular disease (CVD) despite lack of scientific evidence for efficacy and safety. The Trial to Assess Chelation Therapy (TACT) was developed and received funding from the National Institutes of Health (NIH) to ascertain the safety and efficacy of chelation therapy in patients with CVD.

RECENT FINDINGS

This pivotal trial demonstrated an improvement in outcomes in postmyocardial infarction (MI) patients. Interestingly, it also showed a particularly large reduction in CVD events and all-cause mortality in the prespecified subgroup of patients with diabetes. The TACT results may support the concept of metal chelation to reduce metal-catalyzed oxidation reactions that promote the formation of advanced glycation end products, a precursor of diabetic atherosclerosis.

SUMMARY

In this review, we summarize the epidemiological and basic evidence linking toxic metal accumulation and diabetes-related CVD, supported by the salutary effects of chelation in TACT. If the ongoing NIH-funded TACT2, in diabetic post-MI patients, proves positive, this unique therapy will enter the armamentarium of endocrinologists and cardiologists seeking to reduce the atherosclerotic risk of their diabetic patients.

Effect of high-dose oral multivitamins and minerals in participants not treated with statins in the randomized Trial to Assess Chelation Therapy (TACT)

IMPORTANCE

In a prespecified subgroup analysis of participants not on statin therapy at baseline in the TACT, a high-dose complex oral multivitamins and multimineral regimen was found to have a large unexpected benefit compared with placebo. The regimen tested was substantially different from any vitamin regimen tested in prior clinical trials.

OBJECTIVE

To explore these results, we performed detailed additional analyses of participants not on statins at enrollment in TACT.

DESIGN

TACT was a factorial trial testing chelation treatments and a 28-component high-dose oral multivitamins and multiminerals regimen versus placebo in post-myocardial infarction (MI) patients 50 years or older.

PARTICIPANTS

There were 460 (27%) of 1,708 TACT participants not taking statins at baseline, 224 (49%) were in the active vitamin group and 236 (51%) were in the placebo group.

SETTING

Patients were enrolled at 134 sites around the United States and Canada.

INTERVENTION

Daily high-dose oral multivitamins and multiminerals (6 tablets, active or placebo).

MAIN OUTCOME

The primary end point of TACT was time to the first occurrence of any component of the composite end point: all-cause mortality, MI, stroke, coronary revascularization, or hospitalization for angina.

RESULTS

The primary end point occurred in 137 nonstatin participants (30%), of which 51 (23%) of 224 were in the active group and 86 (36%) of 236 were taking placebo (hazard ratio, 0.62; 95% confidence interval, 0.44-0.87; P=.006). Results in the key TACT secondary end point, a combination of cardiovascular mortality, stroke, or recurrent MI, was consistent in favoring the active vitamin group (hazard ratio, 0.46; 95% confidence interval, 0.28-0.75; P=.002). Multiple end point analyses were consistent with these results.

CONCLUSION AND RELEVANCE

High-dose oral multivitamin and multimineral supplementation seem to decrease combined cardiac events in a stable, post-MI population not taking statin therapy at baseline. These unexpected findings are being retested in the ongoing TACT2.

Enhanced vasculotoxic metal excretion in post-myocardial infarction patients following a single edetate disodium-based infusion

Toxic metals have been associated with cardiovascular mortality and morbidity. We have hypothesized that enhanced excretion of vasculotoxic metals might explain the positive results of the Trial to Assess Chelation Therapy (TACT). The purpose of this study was to determine whether a single infusion of the edetate disodium- based infusion used in TACT led to enhanced excretion of toxic metals known to be associated with cardiovascular events.

METHODS

Twenty six patients (post-MI, age > 50 years, serum creatinine ≤ 2.0mg/dL) were enrolled in this open-label study. Urinary levels of 20 toxic metals normalized to urinary creatinine concentrations were measured at baseline in overnight urine collections, for 6h following a placebo infusion of 500mL normal saline and 1.2% dextrose, and for 6h following a 3g edetate disodium-based infusion. Self-reported metal exposure, smoking status, food frequency, occupational history, drinking water source, housing and hobbies were collected at baseline by a metal exposure questionnaire.

RESULTS

The mean age was 65 years (range 51-81 years). All patients were male. 50% had diabetes mellitus and 58% were former smokers. Mean (SD) serum creatinine was 0.95 (0.31) mg/dL. Toxic metals were detected in the baseline urine of >80% of patients. After placebo infusion there were no significant changes in total urinary metal levels. After edetate infusion, total urinary metal level increased by 71% compared to baseline (1500 vs. 2580µg/g creatinine; P<0.0001). The effect of edetate was particularly large for lead (3835% increase) and cadmium (633% increase).

CONCLUSIONS

Edetate disodium-based infusions markedly enhanced the urinary excretion of lead and cadmium, toxic metals with established epidemiologic evidence and mechanisms linking them to coronary and vascular events.

Chronic Toxic Metal Exposure and Cardiovascular Disease: Mechanisms of Risk and Emerging Role of Chelation Therapy

Over the last few decades, there has been a growing body of epidemiologic evidence linking chronic toxic metal exposure to cardiovascular disease-related morbidity and mortality. The recent and unexpectedly positive findings from a randomized, double-blind, multicenter trial of metal chelation for the secondary prevention of atherosclerotic cardiovascular disease (Trial to Assess Chelation Therapy (TACT)) have focused the discussion on the role of chronic exposure to toxic metals in the development and propagation of cardiovascular disease and the role of toxic metal chelation therapy in the secondary prevention of cardiovascular disease. This review summarizes the most recent evidence linking chronic toxic metal exposure to cardiovascular disease and examines the findings of TACT.

Abstract 494: Safety of Chelation Therapy With Edta in Patients With Critical Limb Ischemia: A Pilot Trial of Limb Preservation in Diabetic Patients

Critical limb ischemia (CLI) carries a one year 30% risk of amputation and 25% risk of mortality. Toxic metals are associated with peripheral artery disease and overall cardiac mortality. In The Trial to Assess Chelation Therapy (TACT), EDTA-based chelation improved outcomes in patients with coronary artery disease, with a particular benefit observed in diabetic patients. Here we present the preliminary findings of an open label study aimed at evaluating the safety of EDTA-based chelation, as used in TACT, in diabetic patients with CLI.

Methods: Diabetic patients with CLI Rutherford stage 4 to 5, ≥ 75% stenosis in two or more infra-popliteal arteries and skin perfusion pressure of <40 mmHg in the affected limb were enrolled. Participants received 40 infusions of disodium EDTA over the course of a year, with the first 20 infusions administered bi-weekly and subsequent infusions administered weekly. Laboratory safety assessments were conducted at nine of the infusion visits. Lower extremity pressures and skin perfusion pressures were obtained at baseline and after 20 and 40 infusions using the SensiLase PAD-IQ. HIPAA compliant photographs along with clinical and quality of life questionnaires were also collected.

Results: Three patients (2 women and 1 man) out of 10 planned patients have completed forty EDTA-based infusions. The mean (SD) age and creatinine clearance were 80(7) years and 55(3) mL/min, respectively. All patients had detectable levels of toxic metals in urine; lead was the most abundant toxic metal in the chelated urine. The lowest baseline tissue perfusion pressure in the affected limb was 22, 17 and 19 mmHg for each of the three patients, respectively. Patients have been followed up for an average of 61 (14) weeks. There have been no side effects related to therapy. No patient has been amputated or developed an acute cardiac event. One patient had a PTCA of her affected leg and underwent a debridement of a non-healing ulcer. No significant changes have been detected in skin perfusion pressures during follow up.

Conclusions: Preliminary findings of this open label trial suggest that EDTA treatment in CLI patients is safe. Moreover, after more than a year of follow up, no patient has required any amputation or had any cardiovascular event.

Edetate Disodium-Based Treatment for Secondary Prevention in Post-Myocardial Infarction Patients

An abundance of data, known for decades, is available linking metals, such as lead and cadmium, with cardiovascular disease. However, the idea that these toxic metals could be a modifiable risk factor for atherosclerosis did not become apparent clinically until the completion of the Trial to Assess Chelation Therapy in 2012. This pivotal study was the first double-blind, randomized, controlled trial of its kind to demonstrate a clear improvement in cardiovascular outcomes with edetate disodium therapy in a secondary prevention, post-myocardial infarction population. This effect size was most striking in diabetic patients, where the efficacy of edetate disodium was comparable, if not superior, to that of current guideline-based therapies. Given the economic burden of diabetes and cardiovascular disease, the potential impact of this therapy could be enormous if the results of this study are replicated.

Chelation therapy to treat atherosclerosis, particularly in diabetes: is it time to reconsider?

INTRODUCTION

Case reports and case series have suggested a possible beneficial effect of chelation therapy in patients with atherosclerotic disease. Small randomized trials conducted in patients with angina or peripheral artery disease, however, were not sufficiently powered to provide conclusive evidence on clinical outcomes.

AREAS COVERED

The Trial to Assess Chelation Therapy (TACT) was the first randomized trial adequately powered to detect the effects of chelation therapy on clinical endpoints. We discuss results and future research. Expert commentary: Chelation reduced adverse cardiovascular events in a post myocardial infarction (MI) population. Patients with diabetes demonstrated even greater benefit, with a number needed to treat of 6.5 patients to prevent a cardiac event over 5 years, with a 41% relative reduction in risk of a cardiac event (p = 0.0002). These results led to the revision of the ACC/AHA guideline recommendations for chelation therapy, changing its classification from class III to class IIb. TACT2, a replicative trial, will assess the effects of chelation therapy on cardiovascular outcomes in diabetic patients with a prior myocardial infarction. We are seeking participating sites for TACT2.

Long-term outcome of abdominal aortic aneurysm repair via a retroperitoneal approach

BACKGROUND

A retroperitoneal approach for abdominal aortic aneurysm repair has demonstrated similar short-term postoperative outcomes compared with the transperitoneal approach. However, there is no long-term survival data utilizing exclusively open repair via retroperitoneal approach.

METHODS

We have conducted a retrospective analysis to evaluate the long-term survival of 142 patients with infrarenal aortic aneurysm undergoing elective open surgical repair via a retroperitoneal approach.

RESULTS

Our cohort of patients consisted of 82% males, 59% whites, and a mean age of 72.6±7.7 years. The 30-day mortality rate was 3.5% for open repair via retroperitoneal approach. Post-operative complications were low, with renal failure (9.9%), pulmonary complication (9.9%), and limb ischemia (6.3%) being the most prevalent. Five years after surgery, the cumulative survival rate was 70.1%.

CONCLUSIONS

The elective management of infrarenal aortic aneurysms with open repair via a retroperitoneal approach offers a good prognosis demonstrated with up to 5 year follow up.

Simplified prediction of postoperative cardiac surgery outcomes with a novel score: R2CHADS2

OBJECTIVE

To compare the accuracy of R2CHADS2, CHADS2, and CHA2DS2-VASc scores vs the Society of Thoracic Surgeons (STS) score as predictors of morbidity and mortality after cardiovascular surgery.

METHODS

All patients who underwent cardiothoracic surgery at our institution from January 2008 to July 2013 were analyzed. Only those patients who fulfilled the criteria for STS score calculation were included. The R2CHADS2 score was computed as follows: 2 points for GFR < 60 mL/min/1.73 m(2) (R2), prior stroke or TIA (S2); 1 point for history of congestive heart failure (C), hypertension (H), age ≥75 years (A), or diabetes (D). Area under the curve (AUC) analysis was used to estimate the accuracy of the different scores. The end point variables included operative mortality, permanent stroke, and renal failure as defined by the STS database system.

RESULTS

Of the 3,492 patients screened, 2,263 met the inclusion criteria. These included 1,160 (51%) isolated valve surgery, 859 (38%) coronary artery bypass graft surgery, and 245 (11%) combined procedures. There were 147 postoperative events: 75 (3%) patients had postoperative renal failure, 48 (2%) had operative mortality, and 24 (1%) had permanent stroke. AUC analysis revealed that STS, R2CHADS2, CHADS2, and CHA2DS2-VASc reliably estimated all postoperative outcomes. STS and R2CHADS2 scores had the best accuracy overall, with no significant difference in AUC values between them.

CONCLUSION

The R2CHADS2 score estimates postoperative events with acceptable accuracy and if further validated may be used as a simple preoperative risk tool calculator.

Heavy Metals, Cardiovascular Disease, and the Unexpected Benefits of Chelation Therapy

This review summarizes evidence from 2 lines of research previously thought to be unrelated: the unexpectedly positive results of TACT (Trial to Assess Chelation Therapy), and a body of epidemiological data showing that accumulation of biologically active metals, such as lead and cadmium, is an important risk factor for cardiovascular disease. Considering these 2 areas of work together may lead to the identification of new, modifiable risk factors for atherosclerotic cardiovascular disease. We examine the history of chelation up through the report of TACT. We then describe work connecting higher metal levels in the body with the future risk of cardiovascular disease. We conclude by presenting a brief overview of a newly planned National Institutes of Health trial, TACT2, in which we will attempt to replicate the findings of TACT and to establish that removal of toxic metal stores from the body is a plausible mechanistic explanation for the benefits of edetate disodium treatment.

Quality-of-life outcomes with a disodium EDTA chelation regimen for coronary disease: results from the trial to assess chelation therapy randomized trial

BACKGROUND

The National Institutes of Health.funded Trial to Assess Chelation Therapy (TACT) randomized 1708 stablecoronary disease patients aged .50 years who were .6 months post.myocardial infarction (2003.2010) to 40 infusions ofa multicomponent EDTA chelation solution or placebo. Chelation reduced the primary composite end point of mortality,recurrent myocardial infarction, stroke, coronary revascularization, or hospitalization for angina (hazard ratio, 0.82; 95%confidence interval, 0.69.0.99; P=0.035).

METHODS AND RESULTS

In a randomly selected subset of 911 patients, we prospectively collected a battery of quality-of-life(QOL) instruments at baseline and at 6, 12, and 24 months after randomization. The prespecified primary QOL measures were the Duke Activity Status Index (Table I in the Data Supplement) and the Medical Outcomes Study Short-Form 36 Mental Health Inventory-5. All comparisons were by intention to treat. Baseline clinical and QOL variables were well balanced in the 451 patients randomized to chelation and in the 460 patients randomized to placebo. The Duke Activity Status Index improved in both groups during the first 6 months of therapy, but we found no evidence for a treatment-related difference (mean difference [chelation.placebo] during follow-up, 0.9 [95% confidence interval, .0.7 to 2.6; P=0.27]).There was no statistically significant evidence of a treatment-related difference in the Mental Health Inventory-5 during follow-up (mean difference, 1.0; 95% confidence interval, .0.1 to 2.0; P=0.08). None of the secondary QOL measures showed a consistent treatment-related difference.

CONCLUSIONS

In stable, predominantly asymptomatic coronary disease patients with a history of myocardial infarction,EDTA chelation therapy did not have a detectable effect on QOL during 2 years of follow-up.

CLINICAL TRIAL REGISTRATION

URL: http://clinicaltrials.gov. Unique identifier: NCT00044213.

Usefulness of the CHA2DS2VASc score to predict postoperative stroke in patients having cardiac surgery independent of atrial fibrillation

Despite its association with cardioembolic stroke, atrial fibrillation (AF) appears to be inconsistent as a risk factor for postoperative strokes in patients who underwent cardiac surgery. Furthermore, the relation between AF and the CHA2DS2VASc score has not been definitively established with respect to postoperative stroke. We retrospectively analyzed the records of all cardiac surgery performed at our institution between January 2008 and July 2013. Baseline characteristics, operative data, and postoperative outcomes were compared in patients who developed stroke with those who did not. Previously recognized stroke risk factors, including AF, were analyzed along with the CHADS2 and CHA2DS2VASc scores. A total of 3,492 consecutive patients were identified, of which 2,077 (60%) underwent valve surgery, 915 (26%) had coronary artery bypass grafting, 399 (11%) underwent combined coronary artery bypass grafting and valve procedures, and 101 (3%) had other cardiac operations. Postoperative ischemic strokes occurred in 44 patients (1.2%). The development of a stroke was associated with older age (74 ± 12 vs 69 ± 12, p = 0.008), preoperative antiplatelet medication use (38.6% vs 24.5%, p = 0.043), congestive heart failure (37% vs 20%, p = 0.002), and greater CHADS2 (2.48 ± 1.3 vs 1.98 ± 1.1, p = 0.015) and CHA2DS2VASc scores (4.2 ± 1.8 vs 3.4 ± 1.6, p = 0.002). Multivariable analysis demonstrated that the CHA2DS2VASc score was the only independent predictor of postoperative strokes (odds ratio 1.25; 95% confidence interval 1.05 to 1.5, p = 0.014). In conclusion, the CHA2DS2VASc score appears to predict postoperative strokes independent of the presence of AF.

CHA2DS2-VAS(C) and CHADS2 Scores Predict Adverse Clinical Events in Patients With Pacemakers and Sinus Node Dysfunction Independent of Atrial Fibrillation

BACKGROUND

CHA2DS2-VASc and CHADS2 scores were derived and validated for stroke-risk stratification in patients who have a diagnosis of atrial fibrillation (AF). We hypothesized that these scores would predict adverse cardiovascular events even in the absence of AF.

METHODS

The CHA2DS2-VASc and CHADS2 scores for 2010 patients with sick sinus syndrome who underwent pacemaker implantation and were enrolled in the Mode Selection Trial (MOST) were calculated. The association of these risk scores with main trial end points, including the composite of death and stroke, were evaluated to determine whether the associations differed by history of AF.

RESULTS

Of the 2010 patients, 12% had a CHA2DS2-VASc score of 0-1, 16% had a score of 2, 41% had a score of 3-4, and 31% had a score ≥ 5 (the distribution for CHADS2 was similar); 42% had a clinical history of AF. Both scores were associated with death or stroke (hazard ratio [HR], 1.14; 95% confidence interval [CI], 1.05-1.23 for each 1-point increase in CHA2DS2-VASc; P = 0.001; HR, 1.11; 95% CI, 1.02-1.21 for each 1-point increase in CHADS2; P = 0.016). Association of scores with outcomes of death, stroke, and heart failure hospitalization were not different for patients with vs those without a history of AF (interaction P ≥ 0.55 for CHA2DS2-VASc and ≥ 0.30 for CHADS2).

CONCLUSIONS

Both CHA2DS2-VASc and CHADS2 scores predict risk of death or stroke in patients with sick sinus syndrome, regardless of AF history. These scores could be risk-stratification tools for clinical events that might respond to new therapies—ie, anticoagulation or other interventions—even in the absence of AF.

Metal pollutants and cardiovascular disease: mechanisms and consequences of exposure

INTRODUCTION

There is epidemiological evidence that metal contaminants may play a role in the development of atherosclerosis and its complications. Moreover, a recent clinical trial of a metal chelator had a surprisingly positive result in reducing cardiovascular events in a secondary prevention population, strengthening the link between metal exposure and cardiovascular disease (CVD). This is, therefore, an opportune moment to review evidence that exposure to metal pollutants, such as arsenic, lead, cadmium, and mercury, is a significant risk factor for CVD.

METHODS

We reviewed the English-speaking medical literature to assess and present the epidemiological evidence that 4 metals having no role in the human body (xenobiotic), mercury, lead, cadmium, and arsenic, have epidemiologic and mechanistic links to atherosclerosis and CVD. Moreover, we briefly review how the results of the Trial to Assess Chelation Therapy (TACT) strengthen the link between atherosclerosis and xenobiotic metal contamination in humans.

CONCLUSIONS

There is strong evidence that xenobiotic metal contamination is linked to atherosclerotic disease and is a modifiable risk factor.

Chelation therapy after the trial to assess chelation therapy: results of a unique trial

PURPOSE OF REVIEW

EDTA chelation therapy has been in off-label use for the treatment of atherosclerosis. We review the results of the first large-scale randomized trial of this treatment.

RECENT FINDINGS

The trial to assess chelation therapy was a $30 million National Institutes of Health-funded study of the safety and efficacy of EDTA-based chelation infusions in 1708 post-myocardial infarction (MI) patients. The trial to assess chelation therapy demonstrated a significant (P=0.035) 18% reduction in a combined primary endpoint of death, MI, stroke, coronary revascularization, or hospitalization for angina. In diabetic patients the benefit was more extreme, with a 41% relative reduction in risk (P=0.0002) and a 43% reduction in total mortality (P=0.011). Safety data were favorable. A reduction of oxidative stress by chelation of toxic metals has been proposed as a possible mechanism of action.

SUMMARY

Recent research suggests that EDTA chelation may be a well-tolerated and effective treatment for post-MI patients. Future replication and mechanistic studies are important prior to implementation in all post-MI patients.

Right anterior minithoracotomy versus median sternotomy surgery for native mitral valve infective endocarditis

BACKGROUND AND AIM OF THE STUDY

While concomitant medical and surgical therapy has improved the treatment of infective endocarditis (IE), mortality and postoperative complications remain high. A minimally invasive approach to mitral valve surgery has been associated with decreased morbidity and mortality in high-risk populations. The study aim was to analyze the feasibility of a minimally invasive approach to valve surgery for native mitral valve IE.

METHODS

All heart operations performed between January 2008 and April 2013 at the authors' institution were reviewed retrospectively. The operative times, intensive care unit (ICU) and hospital lengths of stay, postoperative complications, and in-hospital mortality of patients who underwent minimally invasive surgery via a right anterior minithoracotomy for native mitral valve IE were compared to those of a cohort which underwent median sternotomy. A Kaplan-Meier analysis was performed to compare long-term survival between the cohorts.

RESULTS

A total of 50 patients was identified (22 minithoracotomy, 28 median sternotomy). The baseline characteristics, mitral valve pathology and disease burden (annular abscess, cusp perforation, vegetation size, chordal rupture) were similar between the groups. There was no difference in the rate of active versus healed disease. Patients who underwent a minithoracotomy had fewer postoperative composite complications (41% versus 75%, p = 0.02), mainly driven by a decreased incidence of sepsis (0% versus 21%, p = 0.02), as well as less use of intraoperative blood products (59% versus 93%, p = 0.004), higher rates of mitral valve repair (55% versus 25%, p = 0.03), and a shorter ICU length of stay (56 versus 114 h, p = 0.009). Repair of the mitral valve was associated with a decreased risk of postoperative composite complications (OR 0.16, 95% CI 0.04-0.71, p = 0.02). At 2.5 years postoperatively, survival was estimated at 80% and 68% in the minithoracotomy and median sternotomy groups, respectively (p = 0.33).

CONCLUSION

A right anterior minithoracotomy approach for native mitral valve IE provides a safe and feasible alternative to conventional median sternotomy surgery, with improved outcomes conferred by valve repair compared to replacement.

Hybrid approach of percutaneous coronary intervention followed by minimally invasive valve operations

BACKGROUND

A subset of patients requiring coronary revascularization and valve operations may benefit from a hybrid approach of percutaneous coronary intervention (PCI) followed by a minimally invasive valve operation, rather than the standard combined median sternotomy coronary artery bypass grafting (CABG) and a valve operation. This study sought to evaluate the outcomes of this approach in a heterogeneous group of patients with concomitant coronary artery and valvular disease.

METHODS

We retrospectively evaluated 222 consecutive patients with coronary artery and valvular heart disease who underwent PCI followed by elective minimally invasive valve operations at our institution between February 2009 and August 2013.

RESULTS

A total of 136 men and 86 women were identified. The mean age was 74.6 ± 8.2 years, with 181 (81.5%) undergoing 1-vessel, 27 (12.2%) undergoing 2-vessel, and 14 (6.3%) undergoing 3-vessel PCI. Within a median of 38 days (interquartile range [IQR] 18-65 days), 182 (82%) patients underwent primary and 34 (15.3%) underwent repeated valve operations, which consisted of 185 (83.3%) single-valve and 37 (16.7%) double-valve procedures. Operative mortality occurred in 8 patients (3.6%). At a mean follow-up of 16.2 ± 12 months, 6 patients required PCI, with target-vessel revascularization performed in 4 patients (2.1%). Survival at 1 and 4.5 years was 91.9% and 88.3%, respectively.

CONCLUSIONS

In a heterogeneous group of patients, a hybrid approach of PCI followed by minimally invasive valve operations in patients undergoing primary or repeated valve operations can be performed with excellent outcomes.

AT1 receptor blockade for the prevention of cardiovascular events after myocardial infarction

Myocardial infarction is associated with high morbidity and mortality. Multiple therapeutic modalities have been shown to be effective in reducing adverse postmyocardial infarction outcomes. The most prominent drugs that have been used in this group of patients are those that oppose the effects of the renin-angiotensin-aldosterone system. These drugs include beta-blockers, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers and aldosterone blockers. Following initial success with angiotensin-converting enzyme inhibitors in reducing mortality and cardiac remodeling in postmyocardial infarction patients, recent focus has been on adjunctive or alternative use of angiotensin II-receptor antagonists. Multiple large-scale, randomized trials have been conducted in order to compare angiotensin II-receptor antagonists with a combination of angiotensin II-receptor antagonists and angiotensin-converting enzyme inhibitors, and with angiotensin-converting enzyme inhibitors alone in postmyocardial infarction patients and also in heart failure. Although some results are conflicting, the weight of evidence is towards equivalency of these two groups of medicines, provided that the maximum effective dose of the angiotensin II-receptor antagonists is used. The combination of an angiotensin-converting enzyme inhibitor and an angiotensin II-receptor antagonist may have additional benefits for some, but not all, patients; for example, reducing morbidity and mortality in patients with chronic heart failure but not in postmyocardial infarction patients. Indeed, in the postmyocardial infarction setting, the combination appears simply to increase the side effects, without conferring additional benefits. Use of aldosterone antagonists as adjunctive therapy in postmyocardial infarction patients is associated with added benefits in terms of mortality reduction and will become the standard of care in this group of patients.

The use of nitrates in the prevention of contrast-induced nephropathy in patients hospitalized after undergoing percutaneous coronary intervention

Contrast-induced nephropathy (CIN) is a significant cause of morbidity and mortality and effective strategies for its prevention are greatly needed. The purpose of this retrospective, single-center study was to investigate whether nitrate use during percutaneous coronary artery intervention reduces the incidence of CIN. Chart review of all individuals who underwent percutaneous coronary intervention (PCI) from April 2010 to March 2011 was done. Included in the study were patients who were admitted to the hospital after percutaneous coronary artery intervention and had baseline and follow-up creatinine measured. Patients with end-stage renal disease requiring dialysis and those patients with insufficient information to calculate Mehran score were excluded. There were 199 patients who met the eligibility criteria for inclusion in this study. In the identified population, postprocedure renal function was compared between 112 patients who received nitrates prior to coronary intervention and 87 who did not. Baseline characteristics were similar between the 2 groups. Contrast-induced nephropathy was defined as either a 25% or a 0.5 mg/dL, or greater, increase in serum creatinine during the first 48 to 72 hours after contrast exposure. Overall, 43 (21.6%) patients developed CIN post-PCI. Of the patients who received nitrates, 15.2% developed renal impairment when compared to 29.9% in those who did not (odds ratio [OR] = 0.42, 95% confidence interval [CI] 0.21-0.84, P = .014). Multivariate logistic regression analysis demonstrated that nitrate use was independently correlated with a reduction in the development of contrast nephropathy (OR = 0.334, 95% CI 0.157-0.709, P = .004). Additionally, of the various methods of nitrate administration, intravenous infusion was shown to be the most efficacious route in preventing renal impairment (OR = 0.42, 95% CI 0.20-0.90, P = .03). In conclusion, the use of nitrates prior to PCI, particularly intravenous nitroglycerin infusion, may be associated with a decreased incidence of CIN.

Oral high-dose multivitamins and minerals after myocardial infarction: a randomized trial

BACKGROUND

Whether high-dose multivitamins are effective for secondary prevention of atherosclerotic disease is unknown.

OBJECTIVE

To assess whether oral multivitamins reduce cardiovascular events and are safe.

DESIGN

Double-blind, placebo-controlled, 2 x 2 factorial, multicenter, randomized trial. (ClinicalTrials.gov: NCT00044213) SETTING: 134 U.S. and Canadian academic and clinical sites.

PATIENTS

1708 patients aged 50 years or older who had myocardial infarction (MI) at least 6 weeks earlier and had serum creatinine levels of 176.8 mol/L (2.0 mg/dL) or less.

INTERVENTION

Patients were randomly assigned to an oral, 28-component, high-dose multivitamin and multimineral mixture or placebo.

MEASUREMENTS

The primary end point was time to total death, recurrent MI, stroke, coronary revascularization, or hospitalization for angina.

RESULTS

The median age was 65 years, and 18% of patients were women. The qualifying MI occurred a median of 4.6 years (interquartile range [IQR], 1.6 to 9.2 years) before enrollment. Median follow-up was 55 months (IQR, 26 to 60 months). Patients received vitamins for a median of 31 months (IQR, 13 to 59 months) in the vitamin group and 35 months (IQR, 13 to 60 months) in the placebo group (P = 0.65). Totals of 645 (76%) and 646 (76%) patients in the vitamin and placebo groups, respectively, completed at least 1 year of oral therapy (P = 0.98), and 400 (47%) and 426 (50%) patients, respectively, completed at least 3 years (P = 0.23). Totals of 394 (46%) and 390 (46%) patients in the vitamin and placebo groups, respectively, discontinued the vitamin regimen (P = 0.67), and 17% of patients withdrew from the study. The primary end point occurred in 230 (27%) patients in the vitamin group and 253 (30%) in the placebo group (hazard ratio, 0.89 [95% CI, 0.75 to 1.07]; P = 0.21). No evidence suggested harm from vitamin therapy in any category of adverse events.

LIMITATION

There was considerable nonadherence and withdrawal, limiting the ability to draw firm conclusions (particularly about safety).

CONCLUSION

High-dose oral multivitamins and multiminerals did not statistically significantly reduce cardiovascular events in patients after MI who received standard medications. However, this conclusion is tempered by the nonadherence rate.

PRIMARY FUNDING SOURCE

National Institutes of Health.

The effect of an EDTA-based chelation regimen on patients with diabetes mellitus and prior myocardial infarction in the Trial to Assess Chelation Therapy (TACT)

BACKGROUND

The Trial to Assess Chelation Therapy (TACT) showed clinical benefit of an EDTA-based infusion regimen in patients aged ≥50 years with prior myocardial infarction. Diabetes mellitus before enrollment was a prespecified subgroup.

METHODS AND RESULTS

Patients received 40 infusions of EDTA chelation or placebo. A total of 633 (37%) patients had diabetes mellitus (322 EDTA and 311 placebo). EDTA reduced the primary end point (death, reinfarction, stroke, coronary revascularization, or hospitalization for angina; 25% versus 38%; hazard ratio, 0.59; 95% confidence interval [CI], 0.44-0.79; P<0.001) over 5 years. The result remained significant after Bonferroni adjustment for multiple subgroups (99.4% CI, 0.39-0.88; adjusted P=0.002). All-cause mortality was reduced by EDTA chelation (10% versus 16%; hazard ratio, 0.57; 95% CI, 0.36-0.88; P=0.011), as was the secondary end point (cardiovascular death, reinfarction, or stroke; 11% versus 17%; hazard ratio, 0.60; 95% CI, 0.39-0.91; P=0.017). However, after adjusting for multiple subgroups, those results were no longer significant. The number needed to treat to reduce 1 primary end point over 5 years was 6.5 (95% CI, 4.4-12.7). There was no reduction in events in non-diabetes mellitus (n=1075; P=0.877), resulting in a treatment by diabetes mellitus interaction (P=0.004).

CONCLUSIONS

Post-myocardial infarction patients with diabetes mellitus aged ≥50 demonstrated a marked reduction in cardiovascular events with EDTA chelation. These findings support efforts to replicate these findings and define the mechanisms of benefit. However, they do not constitute sufficient evidence to indicate the routine use of chelation therapy for all post-myocardial infarction patients with diabetes mellitus.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00044213.

Percutaneous revascularization and long term clinical outcomes of diabetic patients randomized in the Occluded Artery Trial (OAT)

BACKGROUND

Percutaneous coronary intervention (PCI) of a persistently totally occluded infarct-related artery (IRA) in stable high-risk patients >24h after myocardial infarction (MI) does not reduce the occurrence of death, re-infarction, or heart failure. Diabetic patients are at higher risk for cardiovascular events; we examined their outcomes overall with PCI and optimal medical therapy alone (MED).

METHODS

The long-term (7-year) outcomes of 454 diabetic patients (20.6%) randomized to PCI or MED in the Occluded Artery Trial (OAT) were assessed for the composite primary endpoint of death, re-MI, or New York Heart Association class IV heart failure. Diabetics and non-diabetics were compared and outcomes assessed by treatment strategy.

RESULTS

The 7-year cumulative primary event rate for diabetic patients was 35.0% vs. 19.4% in the non-diabetic cohort (p<0.001). Multivariable analyses revealed diabetes to be an independent predictor (p<0.01) for the primary outcome, fatal or nonfatal recurrent MI, Class IV Heart Failure (HF), and death. The 7-year cumulative primary event rates were 35.3% in the PCI group vs. 34.5% in the medical therapy group in diabetic patients (p=0.19) and 19.3% in the PCI group vs. 19.5% in the medical therapy group in patients without diabetes (p=0.60).

CONCLUSIONS

Despite the higher overall risk conferred by the presence of diabetes, PCI did not improve clinical outcomes in this subpopulation, and is not indicated in otherwise stable patients with a totally occluded infarct-related artery in the sub-acute phase after MI.

Incidence of postoperative acute kidney injury in patients with chronic kidney disease undergoing minimally invasive valve surgery

BACKGROUND

We hypothesize that minimally invasive valve surgery in patients with chronic kidney disease (CKD) is superior to a conventional median sternotomy.

METHODS

We retrospectively analyzed 1945 consecutive patients who underwent isolated valve surgery. Included were patients with CKD stages 2 to 5. In-hospital mortality, composite complication rates, and intensive care unit and total hospital lengths of stay of those who underwent a minimally invasive approach were compared with those who underwent a standard median sternotomy. Resource use was approximated based on intensive care unit and total hospital lengths of stay.

RESULTS

There were 688 patients identified; 510 (74%) underwent minimally invasive surgery, and 178 (26%) underwent a median sternotomy. There was no significant difference in mortality. Minimally invasive surgery was associated with fewer composite complications (33.1% vs 49.4%; odds ratio, 0.5; P ≤ .001), shorter intensive care unit (48 [interquartile range {IQR}, 33-74] hours vs 71 [IQR, 42-96] hours; P < .01), and hospital (8 [IQR, 6-9] days vs 10 [IQR, 8-15] days; P < .001) lengths of stay, and a lower incidence of acute kidney injury (8% vs 14.7%; odds ratio, 0.5; P = .01), compared with median sternotomy. In a multivariable analysis, minimally invasive surgery was associated with a 60% reduction in the risk of development of postoperative acute kidney injury.

CONCLUSIONS

In patients with CKD undergoing isolated valve surgery, minimally invasive valve surgery is associated with reduced postoperative complications and lower resource use.