Gervasio A. Lamas

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.

Outcomes of Minimally Invasive Valve Surgery Versus Median Sternotomy in Patients Age 75 Years or Greater

BACKGROUND Advanced age is a major predictor of poor outcome in patients undergoing valve surgery. We hypothesized that elderly patients who underwent minimally invasive valve surgery for aortic or mitral valve disease would do better when compared with those undergoing the standard median sternotomy. METHODS We retrospectively reviewed 2,107 consecutive heart operations at our institution and identified 203 patients, age 75 years or greater, who underwent isolated mitral or aortic valve surgery. Outcomes of those who had minimally invasive valve surgery through a right minithoracotomy were compared with those who had a median sternotomy. RESULTS Of the 203 patients, 119 (59%) underwent a minimally invasive approach, while 84 (41%) had a median sternotomy. The median postoperative length of stay was 7 days (interquartile range [IQR] 6 to 10) versus 12 days (IQR 9 to 20), p less than 0.001, and intensive care unit length of stay was 52 hours (IQR 44 to 93) versus 119 hours (IQR 57 to 193), p less than 0.001 for minimally invasive and median sternotomy, respectively. In-hospital mortality was 2 (1.7%) versus 8 (9.5%, p=0.01 and composite postoperative morbidity and mortality occurred in 25 (21%) versus 38 (45.2%), p less than 0.001, in minimally invasive versus median sternotomy, respectively. The difference was driven by the following: a lower incidence of acute renal failure, 1 (0.8%) versus 14 (16.7%), p<0.001; prolonged intubation 23 (19.3%) versus 32 (38.1%), p=0.003; wound infections 1 (0.8%) versus 5 (6%), p=0.034; and death. CONCLUSIONS Minimally invasive surgery for isolated valve lesions in elderly patients yields a lower morbidity and mortality when compared with median sternotomy and should be considered when such individuals require valve surgery.

Outcomes of minimally invasive valve surgery versus standard sternotomy in obese patients undergoing isolated valve surgery.

BACKGROUND We hypothesize that composite in-hospital surgical complications are lower in obese patients who undergo minimally invasive valve surgery for aortic and (or) mitral valve disease, when compared with the standard median sternotomy approach. METHODS We retrospectively reviewed 2,288 heart operations done at our institution between January 3, 2005 and January 10, 2010, and identified 160 consecutive obese patients, defined as patients with a body mass index of greater than 30 kg/m(2), who underwent isolated mitral and (or) aortic valve surgery. The outcomes of those who had minimally invasive valve surgery were compared with a matched control group who had valve surgery through a median sternotomy approach. RESULTS Of the 160 patients, 64 underwent the minimally invasive approach and 96 had a median sternotomy. The mean age was 69.4 ± 11 years for the minimally invasive group, and 64.7 ± 11.5 for the median sternotomy group (p = 0.015). Composite postoperative complications occurred in 15 (23.49%) versus 49 (51.0%) patients (p = 0.034) in the minimally invasive group versus median sternotomy, respectively. The difference was driven by a lower incidence of acute renal failure (0 vs 6 patients [6.25%], p = 0.041), prolonged intubation (12 [18.7%] vs 33 [34.3%], p = 0.049), reintubation (3 [4.68%] vs 15 [15.6%], p = 0.032), deep wound infections (0 vs 4 [4.1%], p = 0.098), and death (0 vs 8 [8.3%], p = 0.041), respectively. All patients in the minimally invasive group were alive at 30 days. CONCLUSIONS Minimally invasive surgery for isolated valve lesions in obese patients has a lower morbidity and mortality when compared with the standard median sternotomy approach.

Risk of All-Cause Mortality, Recurrent Myocardial Infarction, and Heart Failure Hospitalization Associated With Smoking Status Following Myocardial Infarction With Left Ventricular Dysfunction

Patients with left ventricular (LV) systolic dysfunction after myocardial infarction (MI) are at particularly high risk for recurrent adverse outcomes. The magnitude of the decrease in risk associated with smoking cessation after MI has not been well described in patients with LV dysfunction after MI. We aimed to quantify the risk decrease associated with smoking cessation in subjects with LV dysfunction after MI. The Survival and Ventricular Enlargement (SAVE) trial randomized 2,231 subjects with LV dysfunction 3 to 16 days after MI. Smoking status was assessed at randomization and at regular intervals during a median follow-up of 42 months. Propensity score-adjusted Cox proportional hazard models were used to quantify the decrease in risk of all-cause mortality, death or recurrent MI, and death or heart failure (HF) hospitalization associated with smoking cessation. In baseline smokers who survived to 6 months without interval events, smoking cessation at 6-month follow-up was associated with a significantly lower adjusted risk of all-cause mortality (hazard ratio [HR] 0.57, 95% confidence interval [CI] 0.31 to 0.91), death or recurrent MI (HR 0.68, 95% CI 0.47 to 0.99), and death or HF hospitalization (HR 0.65, 95% CI 0.46 to 0.92). In conclusion, in patients with LV dysfunction after MI, smoking cessation is associated with a 40% lower hazard of all-cause mortality and a 30% lower hazard of death or recurrent MI or death or HF hospitalization. These findings indicate that smoking cessation is beneficial after high-risk MI and highlight the importance of smoking cessation as a therapeutic target in patients with LV dysfunction after MI.

Preventing ventricular dysfunction in pacemaker patients without advanced heart failure: results from a multicentre international randomized trial (PREVENT-HF)

Previous experimental and clinical studies have consistently suggested that right ventricular (RV) apical pacing has important adverse effects. Ventricular pacing (VP), however, is required, and cannot be reduced in many patients with atrioventricular (AV) block. The PREVENT‐HF study was an international randomized trial that explored differences in left ventricular (LV) remodelling during RV apical vs. biventricular (BIV) pacing in patients with AV block.

Design of the Trial to Assess Chelation Therapy (TACT).

TACT is an National Institutes of Health-sponsored, randomized, double-blind, placebo-controlled, 2 × 2 factorial clinical trial testing the benefits and risks of 40 infusions of a multicomponent disodium EDTA chelation solution compared with placebo and of an oral, high-dose multivitamin and mineral supplement. TACT has randomized and will follow up 1,708 patients for an average of approximately 4 years. The primary end point is a composite of all-cause mortality, myocardial infarction, stroke, coronary revascularization, and hospitalization for angina. A 900-patient substudy will examine quality-of-life outcomes. The trial is designed to have >85% power to detect a 25% relative reduction in the primary end point for each treatment factor. Enrollment began in September 2003 and was completed in October 2010.

Left Main Coronary Artery Acute Thrombosis Related to Energy Drink Intake

A 24-year-old previously healthy black man presented the emergency department with a 10-hour history of nausea, multiple episodes of emesis, palpitations, and severe retrosternal chest pain, described as constant pressure. His symptoms started 1 or 2 hours after he had 3 drinks of vodka mixed with an energy drink at a local party. He used marijuana in the week before but denied cocaine or other recreational drug use. Two of his friends who shared the drinks had similar symptoms but without chest pain. There was no family history of premature coronary artery disease. The patient smokes no more than 5 cigarettes weekly. At admission, his vital signs were blood pressure 138/94 mm Hg, pulse 63 bpm, breathing rate 18 respirations per minute, temperature 36°C, and 99% oxygen saturation on room air. …

Reinfarction after percutaneous coronary intervention or medical management using the universal definition in patients with total occlusion after myocardial infarction: Results from long-term follow-up of the Occluded Artery Trial (OAT) cohort

BACKGROUND The OAT study randomized 2,201 patients with a totally occluded infarct-related artery on days 3 to 28 (>24 hours) after myocardial infarction (MI) to percutaneous coronary intervention (PCI) or medical treatment (MED). There was no difference in the primary end point of death, reinfarction, or heart failure at 2.9 or 6-year mean follow-up. However, in patients randomized to PCI, there was a trend toward a higher rate of reinfarction. METHODS We analyzed the characteristics and types of reinfarction according to the universal definition. Independent predictors of reinfarction were determined using Cox proportional hazard models with follow-up up to 9 years. RESULTS There were 169 reinfarctions: 9.4% PCI vs 8.0% MED, hazard ratio 1.31, 95% CI 0.97-1.77, P = .08. Spontaneous reinfarction (type 1) occurred with similar frequency in the groups: 4.9% PCI vs 6.7% MED, hazard ratio 0.78, 95% CI 0.53-1.15, P = .21. Rates of type 2 (secondary) and 3 (sudden death) MI were similar in both groups. There was an increase in type 4a reinfarctions (related to protocol or other PCI) (0.8% PCI vs 0.1% MED, P = .01) and type 4b reinfarctions (stent thrombosis) (2.7% PCI vs 0.6% MED, P < .001). Multivariate predictors of reinfarction were history of PCI before study entry (P = .001), diabetes (P = .005), and absence of new Q waves with the index infarction (P = .01). CONCLUSIONS There was a trend for reinfarctions to be more frequent with PCI. Opening an occluded infarct-related artery in stable patients with late post-MI may expose them to a risk of subsequent reinfarction related to reocclusion and stent thrombosis.

The Occluded Artery Trial (OAT) Viability Ancillary Study (OAT-NUC): Influence of infarct zone viability on left ventricular remodeling after percutaneous coronary intervention versus optimal medical therapy alone

BACKGROUND The Occluded Artery Trial (OAT) showed no difference in outcomes between percutaneous coronary intervention (PCI) versus optimal medical therapy (MED) in patients with persistent total occlusion of the infarct-related artery 3 to 28 days post-myocardial infarction. Whether PCI may benefit a subset of patients with preservation of infarct zone (IZ) viability is unknown. METHODS AND RESULTS The OAT nuclear ancillary study hypothesized that (1) IZ viability influences left ventricular (LV) remodeling and that (2) PCI as compared with MED attenuates adverse remodeling in post-myocardial infarction patients with preserved viability. Enrolled were 124 OAT patients who underwent resting nitroglycerin-enhanced technetium-99m sestamibi single-photon emission computed tomography (SPECT) before OAT randomization, with repeat imaging at 1 year. All images were quantitatively analyzed for infarct size, IZ viability, LV volumes, and function in a core laboratory. At baseline, mean infarct size was 26% ± 18 of the LV, mean IZ viability was 43% ± 8 of peak uptake, and most patients (70%) had at least moderately retained IZ viability. There were no significant differences in 1-year end-diastolic or end-systolic volume change between those with severely reduced versus moderately retained IZ viability, or when compared by treatment assignment PCI versus MED. In multivariable models, increasing baseline viability independently predicted improvement in ejection fraction (P = .005). There was no interaction between IZ viability and treatment assignment for any measure of LV remodeling. CONCLUSIONS In the contemporary era of MED, PCI of the infarct-related artery compared with MED alone does not impact LV remodeling irrespective of IZ viability.

Staged percutaneous coronary intervention and minimally invasive valve surgery: Results of a hybrid approach to concomitant coronary and valvular disease

BACKGROUND We compared a hybrid approach combining staged percutaneous coronary intervention (PCI) and minimally invasive valve surgery with concurrent valve surgery plus bypass via a median sternotomy approach. METHODS We retrospectively evaluated 65 consecutive patients with coronary disease and surgical valvular heart disease who underwent planned PCI followed within 60 days by minimally invasive valve surgery, and we compared them with 52 matched control patients who underwent conventional bypass grafting and valve surgery. RESULTS There were no in-hospital deaths in the hybrid group, compared with 2 (3.8%) observed in the matched group (P = .11). Death, renal failure, or stroke occurred in 1 (1.5%) in the hybrid group versus 15 (28.8%) in the conventional group (P = .001). The median number of days between PCI and surgery was 24 (interquartile range, 2.5-37). At surgery, 23 hybrid patients were receiving both aspirin and clopidogrel;, 18, clopidogrel alone; 4, aspirin alone; and 22 stopped the antiplatelet agents 5 days before the operation. Intensive care unit hours and total hospital length of stay, including PCI stay for the hybrid group, were less in the hybrid group (P = .001 for both comparisons). In the hybrid group, average blood use was 1.6 ± 1.6 U per patient versus 1.9 ± 2.4 U per patient with conventional surgery (P = .35. There were no reoperations for postoperative bleeding in the hybrid group compared with 2 (3.8%) in the conventional group (P = .43). CONCLUSIONS Staged PCI with minimally invasive valve surgery may offer an alternative to coronary bypass grafting with concurrent valve surgery and should be tested prospectively.