Clozapine-induced myocarditis: recognizing a potentially fatal adverse reaction.

A 46-year-old man with a history of paranoid schizophrenia was admitted with a recurrence of psychotic symptoms. Improvement was noted after the initiation of clozapine. After 2 weeks of clozapine therapy, chest pressure and abnormal cardiac biomarkers (in the presence of a normal coronary angiogram) raised suspicion of myocarditis. That diagnosis was confirmed by means of cardiac magnetic resonance imaging. Discontinuation of the clozapine led to resolution of the cardiac symptoms. Clozapine-induced myocarditis is rare and can be missed for lack of specific clinical findings. In order to prevent disease progression and a possibly fatal outcome, early recognition of the condition and prompt discontinuation of clozapine are necessary.

Comparing stress testing and fractional flow reserve to evaluate presence, location and extent of ischemia in coronary artery disease.

BACKGROUND: FFR provides an accurate and reproducible assessment of the functional severity of coronary stenosis. Whereas stress testing remains the preferred initial modality for assessment of ischemia, there is limited data comparing it with FFR. We sought to determine the correlation between cardiac stress testing and coronary fractional flow reserve (FFR) measurement for assessing the presence, location, and burden of myocardial ischemia in patients referred for evaluation of coronary artery disease (CAD). METHODS: Over 5-year study period, of the 5420 consecutive coronary angiograms that were screened, 326 patients had FFR measurements. Of these, 96 patients with FFR measurements who had a preceding stress test (stress echocardiography [SE] or myocardial perfusion imaging [MPI]) within a year were included. RESULTS: Of the 96 patients, there were 46 (48%) men and 50 (52%) women with a mean age of 61 ± 10 years. SE was performed in 57 (59.3%) and MPI in 32 (40.7%) of patients. FFR was ≤0.79 in 54 (56%) patients. Stress testing had low sensitivity (55%) and specificity (47%) compared to FFR. The concordance between FFR and stress testing was low for both presence (k=0.03) and location (k=0.05) of the ischemic territory. The number of ischemic vascular territories was correctly estimated in only 39% of the stress tests. SE was more likely to overestimate and MPI more likely to underestimate extent of ischemia. CONCLUSIONS: In patients referred for evaluation of CAD, there was poor correlation between stress testing and FFR. A prospective study comparing these two modalities with FFR is needed.

Myocardial ischemia in a patient with peripheral vascular disease, an arteriovenous fistula, and patent coronary artery bypass grafts.

Patients with coronary artery disease often have concurrent peripheral vascular disease. The presence of concurrent vascular pathologies can pose unique challenges among patients who have undergone coronary artery bypass grafting utilizing the left internal mammary artery. We describe a patient with peripheral vascular disease and prior history of coronary artery bypass grafting, who presented with recurrent anginal symptoms and an abnormal stress test despite the absence of significant residual unrevascularized coronary artery disease. Additional evaluation led to the identification of an ipsilateral severe subclavian stenosis with a concomitant ipsilateral upper extremity arteriovenous fistula. Patient's symptoms resolved with the treatment of the underlying vascular lesions.

Clinical and economic studies of eptifibatide in coronary stenting.

Platelet adhesion and aggregation at the site of coronary stenting can have catastrophic clinical and economic consequences. Therefore, effective platelet inhibition is vital during and after percutaneous coronary intervention. Eptifibatide is an intravenous antiplatelet agent that blocks the final common pathway of platelet aggregation and thrombus formation by binding to glycoprotein IIb/IIIa receptors on the surface of platelets. In clinical studies, eptifibatide was associated with a significant reduction of mortality, myocardial infarction, or target vessel revascularization in patients with acute coronary syndrome undergoing percutaneous coronary intervention. However, recent trials conducted in the era of dual antiplatelet therapy and newer anticoagulants failed to demonstrate similar results. The previously seen favorable benefit of eptifibatide was mainly offset by the increased risk of bleeding. Current American College of Cardiology/American Heart Association guidelines recommend its use as an adjunct in high-risk patients who are undergoing percutaneous coronary intervention with traditional anticoagulants (heparin or enoxaparin), who are not otherwise at high risk of bleeding. In patients receiving bivalirudin (a newer safer anticoagulant), routine use of eptifibatide is discouraged except in select situations (eg, angiographic complications). Although older pharmacoeconomic studies favor eptifibatide, in the current era of P2Y12 inhibitors and newer safer anticoagulants, the increased costs associated with bleeding make the routine use of eptifibatide an economically nonviable option. The cost-effectiveness of eptifibatide with the use of strategies that decrease the bleeding risk (eg, transradial access) is unknown. This review provides an overview of key clinical and economic studies of eptifibatide well into the current era of potent antiplatelet agents, novel safer anticoagulants, and contemporary percutaneous coronary intervention.

Right ventricular myocardial performance index derived from tissue Doppler echocardiography is useful in differentiating apical ballooning syndrome from cardiomyopathy due to left anterior descending coronary artery disease.

BACKGROUND: Apical ballooning syndrome (ABS) and obstructive coronary artery disease of the left anterior descending coronary artery (LAD) can both result in similar left ventricular apical wall motion abnormalities. The right ventricle may more likely be involved in ABS, and its careful evaluation may help differentiate the two conditions. Therefore, the aim of this study was to determine the roles of echocardiographic measures of right ventricular (RV) function, namely, Doppler tissue imaging-derived RV index of myocardial performance (RIMP), RV basal free wall systolic excursion velocity (RV S'), and tricuspid annular plane systolic excursion, in differentiating ABS from obstructive LAD disease. METHODS: A total of 80 patients with new extensive apical left ventricular wall motion abnormalities on echocardiography who underwent coronary angiography were identified retrospectively. Patients with insufficient echocardiographic data were excluded (n = 17). Admission clinical and echocardiographic data were compared between patients with obstructive disease of the LAD (LAD group; n = 46) and those with normal coronary arteries (ABS group; n = 17). RESULTS: The ABS group had significantly greater RIMP (1.03 ± 0.22 vs 0.44 ± 0.18, P < .001). In predicting ABS, RIMP > 0.74 had sensitivity of 94%, specificity of 94%, positive predictive value of 84%, and negative predictive value of 98%, with excellent discriminatory ability (area under the receiver operating characteristic curve, 0.96 ± 0.03). Other measures of RV function (i.e., tricuspid annular plane systolic excursion and RV S') were similar between the two groups. CONCLUSIONS: Doppler tissue imaging-derived RIMP may help differentiate ABS from obstructive LAD disease with high accuracy. This easily obtainable measurement may offer a noninvasive tool to differentiate these two conditions.

Recognizing cardiac syncope in patients presenting to the emergency department with trauma.

BACKGROUND: Cardiac syncope is associated with poor outcomes and may result in traumatic injuries. In patients presenting to the emergency department (ED) with trauma, recognizing the cause of syncope is particularly challenging. Also, clinical markers to identify cardiac syncope are not well established. STUDY OBJECTIVES: We sought to evaluate clinical markers that could identify cardiac syncope in patients with traumatic falls derived from a large urban trauma database. METHODS: All patients presenting to the ED during a 10-year study period with a traumatic fall were identified retrospectively. The subset of patients with syncope was ascertained by chart review and defined as cardiac syncope (e.g., presence of dysrhythmia, valvular abnormality), non-cardiac syncope (e.g., vasovagal, neurological), or syncope of unknown cause. RESULTS: Of the 5420 patients with traumatic falls, 180 (3.3%) patients with syncope were identified. Among the 180 patients with syncope, the cause was identified as cardiac in 24 (13%), noncardiac in 58 (32%), and unknown in 98 (54%). Three independent predictors (i.e., risk factors) of cardiac syncope were identified: age >65 years, presence of coronary artery disease, and pathological Q waves. Presence of at least one risk factor accurately predicted cardiac syncope in this population, with a sensitivity of 100%, a specificity of 43%, and a negative predictive value of 100% (area under the receiver operating characteristic curve: 0.80 ± 0.04). CONCLUSION: In patients with traumatic falls and syncope, simple clinical and electrocardiographical variables may identify patients with cardiac causes of syncope. Proper identification of cardiac syncope in this population can potentially prevent recurrence of life-threatening traumatic injury.

Isolated cardiac involvement in primary amyloidosis: presenting as sick sinus syndrome and heart failure.

Cardiac amyloidosis is an infiltrative cardiomyopathy with a grave prognosis. Its clinical manifestations include restrictive cardiomyopathy, diastolic heart failure, conduction defects, and arrhythmias. Isolated cardiac involvement and significant conduction disturbances are reported very infrequently. We report a rare case of isolated cardiac involvement in primary amyloidosis, in a 76-year-old man who initially presented with sick sinus syndrome that necessitated permanent pacemaker insertion. Subsequent symptoms of heart failure led to additional evaluation, including an endomyocardial biopsy that revealed primary cardiac amyloidosis. Medical therapy improved the patient's symptoms, and he was discharged from the hospital in stable condition. In addition to discussing the patient's case, we review the relevant medical literature.

Elevated troponin predicts long-term adverse cardiovascular outcomes in hypertensive crisis: a retrospective study.

BACKGROUND: Hypertensive crisis is associated with poor clinical outcomes. Elevated troponin, frequently observed in hypertensive crisis, may be attributed to myocardial supply-demand mismatch or obstructive coronary artery disease (CAD). However, in patients presenting with hypertensive crisis and an elevated troponin, the prevalence of CAD and the long-term adverse cardiovascular outcomes are unknown. OBJECTIVE: We sought to assess the impact of elevated troponin on cardiovascular outcomes and evaluate the role of troponin as a predictor of obstructive CAD in patients with hypertensive crisis. METHODS: Patients who presented with hypertensive crisis (n = 236) were screened retrospectively. Baseline and follow-up data including the event rates were obtained using electronic patient records. Those without an assay for cardiac Troponin I (cTnI) (n = 65) were excluded. Of the remaining 171 patients, those with elevated cTnI (cTnI ≥ 0.12 ng/ml) (n = 56) were compared with those with normal cTnI (cTnI < 0.12 ng/ml) (n = 115) at 2 years for the occurrence of major adverse cardiac or cerebrovascular events (MACCE) (composite of myocardial infarction, unstable angina, hypertensive crisis, pulmonary edema, stroke or transient ischemic attack). RESULTS: At 2 years, MACCE occurred in 40 (71.4%) patients with elevated cTnI compared with 44 (38.3%) patients with normal cTnI [hazard ratio: 2.77; 95% confidence interval (CI): 1.79-4.27; P < 0.001]. Also, patients with elevated cTnI were significantly more likely to have underlying obstructive CAD (odds ratio: 8.97; 95% CI: 1.4-55.9; P < 0.01). CONCLUSION: In patients with hypertensive crisis, elevated cTnI confers a significantly greater risk of long-term MACCE, and is a strong predictor of obstructive CAD.

Usefulness of left ventricular end-systolic dimension by echocardiography to predict reverse remodeling in patients with newly diagnosed severe left ventricular systolic dysfunction.

In many patients with left ventricular (LV) systolic dysfunction, the LV ejection fraction (LVEF)-a surrogate for reverse remodeling-fails to improve despite optimal medical therapy. The early identification of such patients would allow instituting aggressive treatment, including early therapy with implantable cardioverter defibrillators. We sought to establish the predictors of reverse remodeling in patients with LV systolic dysfunction receiving optimal medical therapy. Patients (n = 568) with newly documented LVEF of ≤0.35, who had ≥1 follow-up echocardiogram after ≥3 months, were evaluated. Reverse remodeling was defined as improvement in LVEF to >0.35. The clinical, laboratory, and echocardiographic data were compared between patients with (n = 263) and without (n = 305) reverse remodeling. The mean follow-up was 27 ± 16 months. Patients who demonstrated reverse remodeling had a significantly greater mean follow-up LVEF (0.51 ± 0.09 vs 0.25 ± 0.08; p <0.001). On multivariate analysis, the baseline LV end-systolic diameter index was the strongest predictor of reverse remodeling (odds ratio 5.79; 95% confidence interval 1.82 to 18.46; p <0.001). Other independent predictors of reverse remodeling were female gender (odds ratio 1.88; 95% confidence interval 1.19 to 2.98; p = 0.007), and nonischemic cardiomyopathy (odds ratio 1.65; 95% confidence interval 1.05 to 2.58; p = 0.03). Baseline LVEF was not an independent predictor of reverse remodeling. In conclusion, among patients with newly diagnosed LV systolic dysfunction, the LV end-systolic diameter index, but not the LVEF, at diagnosis, was a strong predictor of reverse remodeling. Patients with a low likelihood of reverse remodeling might benefit from more aggressive heart failure therapy, including the possible early use of implantable cardioverter defibrillators.

Implantable cardioverter defibrillator (ICD) for polymorphic ventricular tachycardia (VT) due to coronary vasospasm.

We report a case of a young woman who presented with atypical angina. During an episode of chest pain she had a documented run of sustained polymorphic ventricular tachycardia (VT). In addition to medical therapy, she received an ICD to prevent future episodes of sudden cardiac death.