Do omega-3 polyunsaturated fatty acids reduce risk of sudden cardiac death and ventricular arrhythmias? A meta-analysis of randomized trials.

INTRODUCTION: Omega-3 polyunsaturated fatty acids (PUFA) have demonstrated to have antiarrhythmic properties. However, randomized studies have shown inconsistent results. OBJECTIVE: We aimed to analyze the effect of omega-3 PUFA on preventing potentially fatal ventricular arrhythmias and sudden cardiac death. METHODS: Randomized trials comparing omega-3 PUFA to placebo and reporting sudden cardiac death (SCD) or first implanted cardioverter-defibrillator (ICD) event for ventricular tachycardia or fibrillation were included in this study. A meta-analysis using a random effects model was performed and results were expressed in terms of Odds Ratio (OR) and 95% Confidence Interval (CI) after evaluating for interstudy heterogeneity using I(2). The reported data were extracted on the basis of the intention-to-treat principle. RESULTS: A total of 32,919 patients were included in nine trials; 16,465 patients received omega-3 PUFA and 16,454 received placebo. When comparing omega-3 PUFA to placebo, there was nonsignificant risk reduction of SCD or ventricular arrhythmias (OR = 0.82 [95% CI: 0.60-1.21], p = 0.21 I(2) = 49.7%). CONCLUSION: Dietary supplementation with omega-3 PUFA does not affect the risk of SCD or ventricular arrhythmias.

A randomized trial of intravenous n-acetylcysteine to prevent contrast induced nephropathy in acute coronary syndromes.

BACKGROUND: Pharmacokinetic data suggests that the intravenous form of n-acetylcysteine (NAC) may be more effective than the oral formulation in preventing contrast induced nephropathy (CIN). NAC owing to its anti-oxidant properties might be beneficial for patients with acute coronary syndromes (ACS) who are at increased risk for CIN. The aim of this prospective randomized, single-center, double-blind, placebo controlled trial (NCT00939913) was to assess the effect of high-dose intravenous NAC on CIN in ACS patients undergoing coronary angiography and/or percutaneous coronary intervention (PCI). METHODS: We randomized 398 ACS patients scheduled for diagnostic angiography ± PCI to an intravenous regimen of high-dose NAC (1,200 mg bolus followed by 200 mg/hr for 24 hr; n = 206) or placebo (n = 192). The primary end-point was incidence of CIN defined as an increase in serum creatinine concentration ≥ 25% above the baseline level within 72 hr of the administration of intravenous contrast. RESULTS: There was no difference found for the primary end point with CIN in 16% of the NAC group and in 13% of the placebo group (p = 0.40). Change in serum cystatin-C, a sensitive marker for renal function, was 0.046 ± 0.204 in the NAC group and 0.002 ± 0.260 in the control group (p = 0.07). CONCLUSION: In ACS patients undergoing angiography ± PCI, high-dose intravenous NAC failed to reduce the incidence of CIN.

Factors related to a clinically silent peri-procedural drop in hemoglobin with coronary and peripheral vascular interventions.

Clinically evident and subclinical peri-procedural bleeding following interventional therapies are associated with adverse cardiovascular outcomes. The risk factors for clinically evident bleeding have been well described. Despite the well-documented association of adverse outcomes for patients with a subclinical peri-procedural hemoglobin drop, the clinical predictors have not yet been defined. We identified 1176 consecutive patients with a subclinical drop in hemoglobin (fall of ≥ 1 g/dl in patients without clinical bleeding) following percutaneous coronary interventions (PCI) and peripheral vascular interventions (PVI). Multivariate logistic regression analysis was performed. A subclinical peri-procedural hemoglobin drop ≥ 1 g/dl was identified in 41% (400/972) of PCI and in 49% (213/435) of PVI. More than one access site predicted a higher risk of a subclinical drop in hemoglobin in both groups. A body mass index ≥ 30 predicted a lower risk of a subclinical drop in hemoglobin in both groups. For PCI, creatinine clearance < 60 ml/min was associated with a higher risk of a subclinical drop in hemoglobin. In conclusion, clinically silent peri-procedural hemoglobin fall ≥ 1 g/dl is common in patients undergoing both coronary and peripheral percutaneous intervention. Predictors identified in our study will need prospective validation.

Preprocedural hemoglobin predicts mortality following peripheral vascular interventions.

BACKGROUND: Serum hemoglobin (H) level is a well-known predictor of all-cause mortality in patients undergoing percutaneous coronary interventions but has not been studied in patients undergoing peripheral vascular interventions (PVI). We sought to determine the prognostic significance of serum H in patients undergoing PVI. METHODS: We identified 346 consecutive patients undergoing PVI who had a documented a baseline and a postprocedural serum H level over a 33-month period. A multivariate analysis of predictors of 9-month mortality was performed. RESULTS: Of 346 patients identified, there were 28 deaths (8.1%) over a 9-month follow-up period. Periprocedural H change was not associated with death [OR: 1.12 (95% CI: 0.71-1.79), P = NS]. In a multivariate model independent predictors of all-cause mortality were clinical bleeding [OR: 10.7 (95% CI: 0.012-0.769), P = 0.026], emergency intervention [OR: 4.5 (95% CI: 0.07-0.71), P = 0.011], ejection fraction [OR: 1.02 (95% CI: 1.01-1.05), P = 0.020], and preprocedural H [OR: 1.56 (95% CI: 1.19-2.04) P = 0.001]. CONCLUSION: In patients undergoing PVI, preprocedural H was a significant predictor of 9-month all-cause mortality. The highest mortality rate was seen in patients with a preprocedural H level ≤ 10 g/dl. Preprocedural H level can be used in clinical practice to risk stratify patients being considered for PVI. Further investigation is needed to assess if optimization of H level preprocedure improves midterm mortality.

Acute limb ischemia.

Acute limb ischemia is a medical emergency with management options ranging from urgent revascularization to limb amputation. The best patient outcome requires tailoring the treatment to the individual patient. This article describes a step-by-step approach for diagnosis and management of patients presenting with acute limb ischemia.

Drug-eluting coronary stents - focus on improved patient outcomes.

The development of stent has been a major advance in the treatment of obstructive coronary artery disease since the introduction of balloon angioplasty. Subsequently, neointimal hyperplasia within the stent leading to in-stent restenosis emerged as a major obstacle in long-term success of percutaneous coronary intervention. Recent introduction of drug-eluting stents is a major breakthrough to tackle this problem. This review article summarizes stent technology, reviews progress of drug-eluting stents and discusses quality of life, patient satisfaction, and acceptability of percutaneous coronary intervention.

Critical limb ischemia: does long-term patency matter?

In critical limb ischemia (CLI), an underlying principle of treatment is that it takes more oxygenated blood to heal a wound than to maintain tissue integrity. Urgent restoration of perfusion to the ischemic territory, not long-term patency of the target vessel, is the primary treatment goal. However, in patients with CLI treated by surgical bypass, loss of graft patency is associated with poor outcomes. We decided to address the conventional wisdom that restenosis is not a major concern in CLI as long as tissue healing occurs in patients undergoing endovascular revascularization. We retrospectively reviewed the records of consecutive patients treated for CLI with infra-popliteal percutaneous revascularization from 2007 to 2009. Those with prior ipsilateral percutaneous revascularization for CLI formed the study population. Among 29 CLI patients treated for infra-popliteal revascularization, six patients had a history of prior successful ipsilateral revascularization for CLI. All six patients were free of rest pain and ulcers at the 60-day follow-up. The median time interval between the two percutaneous revascularization procedures was 21 months (quartile ranges: 25th = 4.5 months, 75th = 36 months). Five of the six patients had restenosis of a previous lesion, while the sixth patient had a de novo lesion causing recurrent CLI. In conclusion, we found that one in five patients receiving infra-popliteal angioplasty for CLI has had a similar percutaneous revascularization procedure in the past. Among these patients most cases were for restenosis rather than de novo lesions. Further research is needed to determine whether the incidence of recurrent CLI is due to de novo lesions or restenosis. Close clinical follow-up of these patients and maintaining long-term patency with endovascular techniques will likely reduce CLI recurrence.

Predictors of mortality in patients with lower extremity peripheral arterial disease: 5-year follow-up.

BACKGROUND: Peripheral arterial disease (PAD) is associated with increased mortality. Lower extremity (LE) revascularization improves symptoms, but less is known about long-term survival benefits of LE arterial revascularization. METHODS: Two hundred and eighty-three patients with an ankle brachial index (ABI) or=65 years (HR 2.42 [95% CI 1.52-3.85], P < 0.001), history of coronary artery disease (HR 1.67 [95% CI 1.13-2.46], P = 0.010), chronic kidney disease (HR 1.75 [95% CI 1.15-2.67], P = 0.010), and an ABI

The recognition of acute coronary ischemia in the outpatient setting.

BACKGROUND: The missed diagnosis of acute myocardial infarction has been studied in the Emergency Department, but few studies have investigated how often coronary ischemia is correctly identified in the outpatient setting. METHODS: This was a single center retrospective observational study of patients with Health Alliance Plan medical insurance hospitalized at a US tertiary center with acute myocardial infarction in 2004. Outpatient encounters in the 30 days preceding acute myocardial infarction were reviewed by two independent cardiologists for presenting symptoms and diagnostic decision-making in order to classify patient presentations as acute coronary ischemia, stable angina or neither. RESULTS: There were 331 patients with acute myocardial infarction, including 190 (57%) with a primary diagnosis of AMI and evaluated by a physician in the preceding 30 days. This group included 68 patients with 95 documented outpatient encounters by a primary care physician, cardiologist, or other internal medicine specialist which formed the final study population. Mean interval between these encounters and AMI was 17 +/- 11 days. Of these patients, 7 (10%) had symptoms of acute coronary ischemia, 5 (7%) had stable angina symptoms, and 56 (83%) had no symptoms of coronary ischemia at their outpatient encounters. Of the 7 patients with acute coronary ischemic symptoms, 5 were correctly identified and 2 were misidentified. CONCLUSION: A majority of patients with subsequent AMI visit an outpatient provider in the month preceding AMI. However, few present with symptoms of coronary ischemia in the outpatient setting (10%) and these symptoms are not always identified as such.

Multisystem revascularization.

Atherosclerosis affects all major vascular territories. Both surgical and endovascular revascularization techniques have evolved, with more and more patients presenting with disease in multiple vascular beds. This can lead to difficult decision-making and the potential for complications. In this article, we review the available literature to help the clinician decide on optimum sequence, timing, and mode of multisystem revascularization.

Myoglobin and troponin I elevation predict 5-year mortality in patients with undifferentiated chest pain in the emergency department.

BACKGROUND: The long-term prognostic significance of elevated cardiac markers in an undifferentiated patient population with chest pain is unknown. METHODS: Serum troponin I (cTnI), creatine kinase-MB (CK-MB), and myoglobin were measured at presentation in 951 consecutive patients evaluated in the emergency department for possible acute coronary syndrome, and all-cause mortality was measured over 5 years. RESULTS: Final diagnoses included myocardial infarction in 70 (7.4%), unstable angina in 78 (8.2%), stable angina in 26 (2.7%), heart failure in 135 (14.2%), syncope in 61 (6.4%), arrhythmia in 62 (6.5%), and noncardiac diagnoses in 519 (54.6%). Our study population had a mean (+/-SD) age of 63 (+/-16), 434 (46%) were male, 774 (81%) were African American, 408 (43%) had known coronary artery disease, 647 (68%) had hypertension, 244 (26%) had diabetes mellitus, and 237 (25%) had a serum creatinine>or=1.5 mg/dL. At 5 years, there were 349 (36.7%) deaths. In a multivariate model with adjustment for baseline covariates, an elevated cTnI>or=1.0 ng/mL (hazard ratio [HR] 1.7, 95% CI 1.3-2.3) and myoglobin>or=200 ng/mL (HR 1.6, 95% CI 1.2-2.1), but not CK-MB>or=9.0 ng/mL (HR 0.9, 95% CI 0.6-1.3), remained independent predictors of all-cause mortality. Patients with both elevated cTnI and myoglobin had a particularly high mortality rate. CONCLUSION: Among patients evaluated in the emergency department for possible acute coronary syndromes, myoglobin and cTnI at presentation are powerful, independent predictors of long-term (5-year) prognosis.

Prognostic predictors and outcomes in patients with abnormal myocardial perfusion imaging and angiographically insignificant coronary artery disease.

BACKGROUND: Abnormal stress myocardial perfusion imaging studies (SMPI) with angiographically insignificant coronary artery disease (ICAD) have often been labeled "false positive" scans. We evaluated the prognostic predictors and outcomes in an unselected patient population having abnormal SMPI and ICAD (study group) over a 24 month period of follow-up. METHODS: Retrospective study of consecutive patients who had SMPI and subsequent coronary angiography showing ICAD within 6 months of index scan with matched control group with normal scans. Major Adverse Cardiac Events (MACE) were defined as the first occurrence of death or myocardial infarction (MI). Patients were followed up to 24 months from the time of their SMPI to identify the development of MACE. RESULTS: One hundred and twenty five patients formed the study group and one hundred and thirty six patients formed the control group. Over a two-year follow up, approximately 13% of the study group had MACE as compared to 4.2% in the control group (P = .022). Abnormal SMPI, EF < 40% and chronic kidney disease (GFR < 60 ml/min) were independent predictors of MACE in the study group. In multivariate analysis for MACE prediction, chronic kidney disease remained the sole independent predictor regardless of size or severity of perfusion abnormalities (P = <.001). CONCLUSION: Patients with abnormal SMPI and ICAD have a 13% event rate of MACE over a two-year follow up. CKD seems a very important marker of a higher risk subgroup amongst such patients.

A rare side effect of transesophageal echocardiography: methemoglobinemia from topical benzocaine anesthesia.

BACKGROUND: Benzocaine induced methemoglobinemia is an uncommon, potentially fatal condition. CASE REPORT: A 44-year-old woman with a history of hepatitis C and intravenous drug use was referred for transesophageal echocardiography for bacteremia evaluation. During induction of topical anesthesia with benzocaine spray she became cyanotic. Pulse oximetry revealed marked desaturation (75%) but was discordant from arterial blood O(2) saturation (99%). Due to clinical suspicion, methemoglobin level was measured and noted to be 69%. The patient was treated with 2 mg/kg of methylene blue intravenously with resolution of her symptoms. CONCLUSION: Physicians using topical anesthesia in endoscopic suites should be aware of this rare, potentially life-threatening treatable condition. High clinical suspicion and availability of methylene blue in endoscopy suites will facilitate prompt diagnosis and treatment.

A meta-analysis of randomized control trials comparing minimally invasive direct coronary bypass grafting versus percutaneous coronary intervention for stenosis of the proximal left anterior descending artery.

Percutaneous intervention (PCI) and minimally invasive direct coronary bypass grafting (MIDCAB) are both well-accepted treatment options for isolated high-grade stenosis of proximal left anterior descending coronary artery. Small studies comparing the two modalities have yielded conflicting results. We performed a meta-analysis of randomized control trials to compare percutaneous intervention with minimally invasive coronary bypass grafting for isolated proximal left anterior descending artery stenosis. Five randomized trials with a total of 711 patients and average follow-up of 2.3 years were included in the analysis; 380 patients received stents and 331 underwent surgery. Only one trial used drug eluting stents. There were a small number of events overall in each trial. Difference between mortality was 12 events versus 15 between the PCI versus MIDCAB group. Similarly, the difference in myocardial infarction was 14 versus 10, and target vessel revascularization was 56 versus 19. The relative risk for stenting versus MIDCAB was 0.96 [(95% CI: 0.47, 1.99), p=0.92, I(2)=17.5%], for mortality and myocardial infarction, 0.77 [(95% CI: 0.30, 2.01), p=0.60, I(2)=10.4%] for mortality and 1.81 [(95% CI: 0.80, 4.06), p=0.15, I(2)=65.9%] for the composite end point of mortality, myocardial infarction and target vessel revascularization. Excluding the trial with drug eluting stents the relative risk for the composite outcome of mortality, myocardial infarction and target vessel revascularization was significantly higher for PCI [RR=2.27 (95% CI: 1.32, 3.90), p=0.003, I(2)=18.9%]. Overall mortality and myocardial infarction rates are similar for bare metal stents versus MIDCAB, but surgery was associated with significantly lower rates of repeat revascularization. The number of randomized patients and events were small. The effect of drug eluting stents might close the gap of repeat revascularization compared to MIDCAB for this disease.

Modified thrombolysis in myocardial infarction (TIMI) risk score to risk stratify patients in the emergency department with possible acute coronary syndrome.

OBJECTIVE: To assess the prognostic utility of the Thrombolysis in Myocardial Infarction (TIMI) risk score in patients in the emergency department (ED) evaluated for possible acute coronary syndrome (ACS). BACKGROUND: The ability of the TIMI risk score to risk stratify patients at initial presentation in the ED with chest pain of unclear etiology is uncertain. METHODS: We investigated the prognostic utility of the TIMI risk score in 947 consecutive patients evaluated in the ED for possible ACS. A multivariate analysis was done to evaluate the independent predictive power of the individual components of the TIMI risk score to predict an adverse event at 30 days (all-cause death, myocardial infarction, and coronary revascularization). RESULTS: There were 151 (16%) patients diagnosed with ACS. At 30 days there were 48 (5%) deaths, 84 (9%) myocardial infarctions, and 49 (5%) coronary revascularization procedures. The mean TIMI risk score was significantly higher in patients with an adverse event compared with those without (2.6 +/- 1.3 vs. 1.7 +/- 1.2, P < 0.0001). Four of the 7 TIMI risk factors (age > or = 65 years, ST segment deviation > or = 0.5 mm elevated troponin I, and coronary stenosis > or = 50%) were independently associated with adverse events. A simplified TIMI risk score was computed and was found to have similar prognostic ability as the 7 variable TIMI risk score. CONCLUSION: A modified TIMI risk score may simplify risk stratification of ED patients with undifferentiated chest pain.

Isolated left pulmonary artery stenosis due to extrinsic compression by intra thoracic tumor: recognition of unusual Doppler flow pattern and correlation with computed tomography.

Pulmonary artery compression in adults resulting from tumors is an uncommon condition often associated with poor prognosis. Among the imaging modalities used for diagnosis, the role of trans thoracic echocardiography in identifying secondary pulmonic stenosis due to extrinsic or intrinsic compression and more importantly the physiologic significance has been increasingly recognized. We describe here a case of isolated left pulmonary artery stenosis which was initially suspected based on classic echocardiographic features of obstruction of pulmonary artery and subsequently confirmed by CT imaging. This case illustrates the versatility of trans thoracic echocardiography in diagnosing incidental abnormalities with potential significant consequences.