Aryan N. Mooss

ACC/AHA 2002 Guideline Update for Exercise Testing: Summary Article: A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee to Update the 1997 Exercise Testing Guidelines)

The American College of Cardiology (ACC)/American Heart Association (AHA) Task Force on Practice Guidelines regularly reviews existing guidelines to determine when an update or full revision is needed. This process gives priority to areas where major changes in text, and particularly recommendations, are mentioned on the basis of new understanding or evidence. Minor changes in verbiage and references are discouraged. The ACC/AHA guidelines for exercise testing that were published in 1997 have now been updated. The full-text guidelines incorporating the updated material are available on the Internet (www.acc.org or www.americanheart.org) in both a version that shows the changes in the 1997 guidelines in strike-over (deleted text) and highlighting (new text) and a “clean” version that fully incorporates the changes. This article describes the 10 major areas of change reflected in the update in a format that we hope can be read and understood as a stand-alone document. The table of contents from the full-length guideline (see next page) indicates the location of these changes. Interested readers are referred to the full-length Internet version to completely understand the context of these changes. All new references appear in boldface type; all original references appear in normal type.⇓ View this table: Table of Contents The ACC/AHA classifications, I, II, and III are used to summarize indications as follows: Class I: Conditions for which there is evidence and/or general agreement that a given procedure or treatment is useful and effective. Class II: Conditions for which there is conflicting evidence and/or a divergence of opinion about the usefulness/efficacy of a procedure or treatment. IIa: Weight of evidence/opinion is in favor of usefulness/efficacy. IIb: Usefulness/efficacy is less well established by evidence/opinion. Class III: Conditions for which there is evidence and/or general agreement that the procedure/treatment is not useful/effective and in some cases may be harmful. In the original …

Acetylcysteine in the prevention of contrast-induced nephropathy after coronary angiography

BACKGROUND Contrast-induced nephropathy (CIN) after coronary angiography is associated with increased morbidity and mortality rates. Preliminary studies with N-acetylcysteine (NAC) have found conflicting results in the prevention of CIN in patients undergoing coronary angiography. This study was designed to evaluate the efficacy and safety of NAC in the prevention of CIN in patients undergoing coronary angiography. METHODS This study was prospective, randomized, double-blind, and placebo-controlled. Patients referred for elective coronary angiography with a baseline creatinine clearance level <50 mL/min and serum creatinine >1.2 mg/dL were randomly assigned to 1500 mg NAC or placebo, starting the evening before angiography and given every 12 hours for 4 doses. The primary study end point was the development of CIN, which was defined as an increase of >0.5 mg/dL or an increase of > or =25% in serum creatinine over baseline within 48 hours of angiography. Secondary end points included changes in serum creatinine and blood urea nitrogen, requirement of dialysis, side effects of study medication, hospital length of stay, and hospital charges. RESULTS CIN occurred in 8.2% (4/49) of patients taking NAC and 6.4% (3/47) of patients taking placebo. Changes in BUN and serum creatinine from baseline were not significantly different in the two treatment groups. Baseline BUN and volume of contrast were the only independent predictors of CIN. More patients with diabetes had development of CIN (5/43; 12%) compared with nondiabetic patients (2/52; 4%), but the difference was not significant (P =.15). The incidence of CIN in diabetic patients was not different in the two treatment groups. No patient with development of CIN required dialysis. Side effects (mostly gastrointestinal) occurred in 16% of patients taking NAC and in none of the patients taking placebo. Length of stay and hospital charges were not different between the treatment groups. CONCLUSIONS In patients with reduced renal function undergoing elective coronary angiography, NAC does not reduce the risk of CIN.

Outcomes After Carotid Artery Stenting and Endarterectomy in the Medicare Population

Background and Purpose— Carotid artery stenting (CAS) is an alternative to carotid endarterectomy (CEA) for stroke prevention. The value of this therapy relative to CEA remains uncertain. Methods— In 10 958 Medicare patients aged 66 years or older between 2004 and 2006, we analyzed in-hospital, 1-year stroke, myocardial infarction, and death rate outcomes and the effects of potential confounding variables. Results— CAS patients (87% were asymptomatic) had a higher baseline risk profile, including having a higher percentage of coronary and peripheral arterial disease, heart failure, and renal failure. In-hospital stroke rate (1.9% CAS versus 1.4% CEA; P=0.14) and mortality (CAS 0.9% versus 0.6% CEA; P=0.20) were similar. By 1 year, CAS patients had similar stroke rates (5.3% CAS versus 4.1% CEA; P=0.12) but higher all-cause mortality rates (9.9% CAS versus 6.1% CEA; P<0.001). Using Cox multivariable models, there was a similar stroke risk (hazard ratio, 1.28; 95% CI, 0.90–1.79) but CAS patients had a significantly higher mortality (HR, 1.32; 95% CI, 1.02–1.71). Sensitivity analyses suggested that unmeasured confounders could be responsible for the mortality difference. In multivariable analysis, stroke risk was highest in the patients symptomatic at the time of revascularization. Conclusions— CAS patients had a similar stroke risk but an increased mortality rate at 1 year compared with CEA patients, possibly related to the higher baseline risk profile in the CAS patient group.

Safety of Esmolol in Patients with Acute Myocardial Infarction Treated with Thrombolytic Therapy Who Had Relative Contraindications to Beta-Blocker Therapy

OBJECTIVE: This study was conducted to evaluate the safety of esmolol in 114 patients treated with thrombolytic therapy for acute myocardial infarction who also had relative contraindications to beta-blockade, and the predictive value of patient tolerance to esmolol and subsequent patient tolerance of oral beta-blocker therapy. PATIENTS: One hundred and fourteen patients with myocardial infarction documented by enzyme concentrations and electrocardiographic changes who also had relative contraindications to beta-blockade. METHODS: Esmolol was initiated during acute myocardial infarction for myocardial ischemia (n=88), hypertension (n=13), or supraventricular tachycardia (n=13). Relative contraindications to beta-blocker therapy included either active signs/symptoms of left ventricular dysfunction or a history of congestive heart failure (n=40), a history of chronic obstructive pulmonary disease or asthma (n=31), bradycardia (HR <60 beats/min; n=18), peripheral vascular disease (n=15), or hypotension (systolic BP <100 mm Hg; n=14). RESULTS: During initial esmolol dose titration, 69 patients tolerated 300 μg/kg/min, 12 patients tolerated 200 μg/kg/min, 17 patients tolerated 100 μg/kg/min, and 16 patients tolerated 50 μg/kg/min. Twenty-eight patients (25 percent) developed dose-limiting adverse effects during esmolol maintenance infusions. Sixteen patients required esmolol dose reduction and 12 required esmolol discontinuation. Adverse effects reversed within 30–45 minutes following dose reduction or discontinuation. The 86 patients who tolerated esmolol infusions without dose reduction or drug discontinuation were subsequently treated with oral beta-blockers. Eleven of these patients (13 percent) developed adverse effects requiring oral beta-blocker discontinuation. Nine of these patients had tolerated only 50 μg/kg/min of esmolol, and the other 2 patients had tolerated only 100 μg/kg/min. CONCLUSIONS: Esmolol can be used safely in most patients treated with thrombolytic therapy for acute myocardial infarction who have relative contraindications to beta-blockers. Tolerance to higher maintenance doses of esmolol is a good predictor of subsequent outcome with oral beta-blocker therapy.

Efficacy and tolerance of high-dose intravenous amiodarone for recurrent, refractory ventricular tachycardia

High-dose intravenous amiodarone was given to 35 patients with recurrent life-threatening ventricular tachycardia (VT) refractory to conventional antiarrhythmic agents. Intravenous amiodarone was given as a 5 mg/kg dose over 30 minutes followed by 20 to 30 mg/kg/day as a constant infusion for 5 days. Twenty-two (63%) patients responded to intravenous amiodarone. All 22 responders received oral amiodarone. Thirteen (59%) continue to receive oral amiodarone after an average follow-up of 19 months, 4 (18%) had sudden cardiac death on oral amiodarone, 2 (9%) died while receiving amiodarone, secondary to left ventricular failure, and 3 (14%) discontinued amiodarone because of side effects. Of the 13 (37%) nonresponders, 10 died in the hospital while receiving intravenous amiodarone, secondary to lethal arrhythmia. Three nonresponders were discharged from the hospital; 2 with automatic cardioverter/defibrillators and 1 receiving a combination of antiarrhythmic agents. Serious adverse events occurred in 13 (37%) patients during intravenous amiodarone therapy. These included hypotension in 8 patients, symptomatic bradycardia in 4 patients and sinus arrest with bradycardia and hypotension in 1 patient. Minor side effects occurred in 23 (66%) patients. In conclusion, high dose intravenous amiodarone is effective in most patients with recurrent, sustained VT but is associated with an unacceptably high incidence of serious adverse events. The optimal dose and duration of intravenous amiodarone for patients with recurrent, refractory sustained VT remain unknown.

Digoxin-lnduced positive exercise tests: Their clinical and prognostic significance

Abstract To evaluate the influence of digoxin on the results of exercise testing and the prognostic significance of digoxin-induced positive exercise tests, 98 healthy men, aged 22 to 70 years, were studied. All had normal initial exercise test results. All took digoxin, 0.25 mg daily, for 14 days, and then performed daily exercise tests until each had a negative test response. Five years after these initial tests, a medical history was obtained from 92 of the 98 subjects, and 76 subjects performed repeat exercise tests. Six subjects were lost to follow-up study. Twenty-five percent of subjects (22 of 98) had a digoxin-induced positive exercise test. There was a direct relation between age and the incidence of digoxin-positive tests. The incidence of digoxin-positive tests in men over age 60 years was 100 percent. By 30 seconds after exercise no subject had greater than 1.9 mm S-T depression. No test remained positive for more than 6 minutes after exercise was discontinued. No test was positive 12 days after digoxin was withdrawn. With logistic regression analysis, it was possible to estimate the probability that a subject would have a digoxin-induced positive test. No subject had had a cardiovascular event at follow-up study, but five subjects had a positive repeat exercise test. Four of these subjects had had a digoxin-positive test initially. It is concluded that (1) useful information can be obtained from exercise studies of patients who receive digoxin, (2) the probability that a positive exercise test is due to digoxin can be estimated, (3) to remove the exercise-induced electrocardiographic effect, the drug should be withdrawn for 12 days, and (4) digoxin may unmask subclinical coronary arterial stenosis.

Diagnostic and prognostic significance of exercise-induced premature ventricular complexes in men and women: A four year follow-up

Two hundred eighty patients (197 men and 83 women) with normal rest electrocardiograms and no history of prior myocardial infarction were referred for evaluation of chest pain. It was found that exercise-induced premature ventricular complexes had a lower sensitivity, specificity, positive predictive value and negative predictive value in predicting significant coronary artery disease than exercise-induced ST segment depression greater than or equal to 1 mm. The incidence of exercise-induced premature ventricular complexes was not significantly different in patients with no significant coronary artery disease, single vessel disease or multivessel disease. The site of origin of exercise-induced premature ventricular complexes was not helpful in predicting the presence or severity of coronary artery disease. At a mean follow-up period of 47.1 months, exercise-induced premature ventricular complexes did not predict coronary events (cardiac death or nonfatal myocardial infarction) in men or women.

Effect of omega-3 fatty acid supplementation on the arachidonic acid:eicosapentaenoic acid ratio.

Study Objectives. To determine the baseline arachidonic acid: eicosapentaenoic acid (AA:EPA) ratio in patients with coronary artery disease and healthy subjects, and whether supplementation of omega‐3 fatty acids, administered as fish oil capsules, affects this ratio.

Time to treatment and cost of thrombolysis: a multicenter comparison of tPA and rPA.

Study Objective: This study reports a comparison of the time to treatment and cost of administration of alteplase (tPA) and reteplase (rPA) in patients with acute myocardial infarction (MI).Design: Retrospective chart review.).Setting: Hospital emergency department.).Interventions: A retrospective chart review of 500 MI patients who received alteplase or reteplase was performed. A comparison of time from presentation in the emergency department to start of treatment was performed, and the cost of administration of drugs, including cost of supplies, monitoring time, and IV line complications, was calculated for each drug.).Results: The time from presentation to start of treatment was significantly shorter for reteplase than alteplase (51 vs 34 min). This difference resulted from a shorter decision to treat to start of treatment time for reteplase (11 min) compared to alteplase (31 min). The cost of administration of alteplase ranged from

Effectiveness of Thrombolytic Therapy in Acute Embolic Stroke due to Infective Endocarditis

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