Left Internal Mammary Artery-to-Pulmonary Vein Fistula: A Rare Cause of Unstable Angina.

The incidence of acquired left internal mammary artery-to-pulmonary vein fistulas has been increasing in the last few decades. This has been attributed to the increase in coronary artery bypass surgery (CABG). The most commonly reported symptoms are angina and dyspnea. The timing of the presentation varies widely from a few months to several years after CABG. Medical management is the treatment of choice and usually controls the symptoms in most patients. Percutaneous intervention is, however, indicated when medical therapy fails. In this case report, a 72-year-old man with a history of CABG presented with progressively worsening chest pain and dyspnea. Troponin was negative and the electrocardiogram showed no acute ischemic changes. He was found to have left internal mammary artery-to-pulmonary vein fistula on coronary angiogram. His symptoms improved upon intensifications of his guideline-directed therapy for coronary artery disease. This represents an unusual cause of unstable angina.

Clinical Determinants of Myocardial Injury, Detectable and Serial Troponin Levels among Patients with Hypertensive Crisis.

Introduction There is a high prevalence of hypertensive crisis with myocardial injury, as evidenced by elevation in cardiac troponin levels. The risk factors predisposing patients to developing a myocardial injury, detectable troponin, and increase in serial troponin in this population are not known. Methods A retrospective study was designed to include all patients, presenting to the emergency room, diagnosed with hypertensive crisis, using International Classification of Diseases, 10th revision, Clinical Modification (ICD-10-CM) codes between 2016-2018 (n=467). Logistic regression was used to determine the important predictors of myocardial injury evidenced by troponin elevation >99th percentile of upper reference level (URL), detectable troponin (> 0.015 ng/ml), and increase in serial troponin levels. Results The 99th percentile of the initial troponin level among all patients was 0.433 ng/ml. A total of 15% had a myocardial injury, and the significant risk factors associated with it were body mass index (BMI) < 30 kg/m2 (odds ratio [OR] 0.50, confidence interval [CI] 0.28-0.89), congestive heart failure (CHF; OR 4.28, CI 2.21-8.25) and prior use of aspirin (OR 1.98, CI 1.08-3.63). About 35% had detectable troponin, and BMI < 30 kg/m2 (OR 0.62, CI 0.40-0.97), CHF (OR 3.49, CI 2.06-5.9), elevated creatinine (OR 1.17, CI 1.02-1.34) and age <61 years (OR 0.59, CI 0.38-0.94) were associated with it. The factors associated with an increase in serial troponin were BMI < 30 Kg/m2 (OR 0.56, CI 0.36-0.87), CHF (OR 1.78, CI 1.06-3.0), coronary artery disease (CAD; OR 2.08, CI 1.28-3.36) and non-Caucasian race (OR 0.52, CI 0.29-0.93). Conclusion About one-third of patients with the hypertensive crisis have detectable troponin. Still, among these, less than half have troponin levels >99th percentile URL, and the majority of these patients have minimal changes in serial troponin. Low BMI was associated with higher initial and serial troponin levels, and this obesity paradox was stronger among females and older patients.

Outcomes of primary percutaneous intervention of the unprotected left main coronary artery stenosis in myocardial infarction.

OBJECTIVE: The aim of our study was to examine the 30-day and 1-year survival rate for patients undergoing percutaneous coronary artery intervention (PCI) of unprotected left main (ULM) stenosis by the presence (acute myocardial infarction [AMI] group) or absence (non-AMI group) of AMI at the time of hospital admission. METHODS: We retrospectively reviewed 64 patients undergoing PCI of ULM stenosis at our regional heart institute between 2000 and 2008. Patients had no history of coronary artery bypass grafting. RESULTS: Thirty-six men and 28 women underwent PCI for ULM stenosis. Overall Kaplan-Meier survival at 30 days and 1 year was 71.5% and 57.8%, respectively. Thirty-three patients (51.6%) presented with AMI. Those with AMI had lower survival at both 30 days (59.2 vs 83.9%; P = 0.04) and 1 year (45.2 vs 70.2%; P = 0.04) compared with those without AMI. Compared with a lesion involving only the ostial/mid LM, diffuse disease (N = 11) was associated with an increased mortality at 1 year (hazard ratio 0.27; 95% confidence interval 0.09-0.79). A stent size >3 mm was associated with lower mortality at 1 year (hazard ratio 0.42; 95% confidence interval 0.19-0.93). CONCLUSIONS: We found that AMI at presentation was significantly associated with higher mortality in patients undergoing ULM stenting. LM lesion location and stent size were both significantly associated with mortality. ULM stenting is an option in patients who are unable to undergo coronary artery bypass grafting, but patients should understand the overall high risk of mortality, particularly if they present with AMI.

Quality improvement in an anticoagulation clinic: development of a new treatment protocol.

We sought to improve patient outcomes and efficiency in our anticoagulation clinic through development of a new protocol for managing heart valve patients with subtherapeutic international normalized ratio (INR) tests. The new protocol standardized use of 1 anticoagulation agent while warfarin was retitrated, timelines for INR retesting, and target INR levels depending on the type of valve implanted. The new protocol provided significant improvements in patient care; however, outcomes for clinic operating efficiency were mixed.

Acetaminophen combinations protect against iron-induced cardiac damage in gerbils.

This study tested if acetaminophen, N-methyl-D-glucamine dithiocarbamate (NMGDTC), deferoxamine, and combinations of these agents reduce excess iron content, prevent iron-induced pathology, reduce cardiac arrhythmias, and reduce mortality in iron-overloaded gerbils. Eight groups of 16 gerbils received iron dextran injections (ferric hydroxide dextran complex, 120 mg/kg, ip) or saline solution (controls) twice/wk for 8 wk. The 8 groups were treated every Monday, Wednesday, and Friday with one of the following: saline control, acetaminophen, 150 mg/kg, ip), acetaminophen (150 mg/kg, po), deferoxamine, 83 mg/kg, ip), NMGDTC (200 mg/kg, ip), or combinations of acetaminophen (75 mg/kg) with deferoxamine (42 mg/kg, each ip, separately) or acetaminophen (75 mg/kg) with NMGDTC (100 mg/kg, each ip, separately). The treatments were given 4 hr after each iron injection on days when both iron administration and treatment occurred during iron overloading (8 wk) and were continued 4 wk thereafter. Echocardiography (ECHO) was used to evaluate iron-induced cardiac changes and detect arrhythmias. Acetaminophen and NMGDTC, or combinations thereof, reduced cardiac and hepatic excess iron content as measured by inductively coupled plasma atomic emission spectrometry (ICP-AES). Acetaminophen was effective whether administered po or ip. Acetaminophen treatment had a positive inotropic effect on cardiac function. Acetaminophen-deferoxamine combination conferred equal cardioprotection as acetaminophen or deferoxamine alone, was equally able to remove hepatic iron, and was superior to either acetaminophen or deferoxamine in removing cardiac iron from iron-overloaded gerbils. Acetaminophen-NMGDTC combination was also effective in removing cardiac and hepatic iron and protecting against iron-induced cardiac damage. ECHO evaluation of iron-overloaded, untreated gerbils demonstrated a high incidence of cardiac arrhythmias, usually PVCs (10/16 = 63%), and mortality prior to completion of the experiment (4/16 = 25%). All treatments except deferoxamine, alone, reduced the incidence of cardiac arrhythmias and deaths. All treatments reduced iron-induced increases in hepatic and cardiac weights. This study demonstrates injection alternates that are equally or more effective than deferoxamine injections and shows oral acetaminophen to be effective in treatment of iron-overload and associated cardiac complications.

Age-associated changes in hearts of male Fischer 344/Brown Norway F1 rats.

Aging is associated with left ventricular hypertrophy, dilatation, and fibrosis of the heart. The Fischer 344/Brown Norway F1 (F344/BNF1) rat is recommended for age-related studies by the National Institutes on Aging because this hybrid rat lives longer and has a lower rate of pathological conditions than inbred rats. However, little is known about age-associated changes in cardiac and aortic function and structure in this model. This study evaluated age-related cardiac changes in male F344/BNF1 rats using ECHO, gross, and microscopic examinations. Rats aged 6-, 30-, and 36-mo were anesthetized and two-dimensional ECHO measurements, two-dimensional guided M-mode, Doppler M-mode, and other recordings from parasternal long- and short-axis views were obtained using a Phillips 5500 ECHO system with a 12 megahertz transducer. Hearts and aortas from sacrificed rats were evaluated grossly and microscopically. The ECHO studies revealed persistent cardiac arrhythmias (chiefly PVCs) in 72% (13/18) of 36-mo rats, 10% (1/10) of 30-mo rats, and none in 6-mo rats (0/16). Gross and microscopic studies showed left ventricular (LV) dilatation, borderline to mild hypertrophy, and areas of fibrosis that were common in 36-mo rats, less evident in 30-mo rats, and absent in 6-mo rats. Aging was associated with mild to moderate decreases of LV diastolic and systolic function. Thus, male F344/BN F1 rats demonstrated progressive age-related (a) decline in cardiac function (diastolic and systolic indices), (b) LV structural changes (chamber dimensions, volumes, and wall thicknesses), and (c) persistent arrhythmias. These changes are consistent with those in humans. The noninvasive ECHO technique offers a means to monitor serial age-related cardiac failure and therapeutic responses in the same rats over designated time intervals.

Effect of experimental hyperhomocysteinemia on cardiac structure and function in the rat.

Male Sprague-Dawley rats were subjected for 2 weeks to daily injections of homocysteine (Hcy), which increased plasma Hcy approximately 2-fold. Echocardiography indicated significant increases in left ventricular diastolic (13%) and systolic (31%) dimensions and decreases in posterior wall thickness (diastolic, -17%; systolic, -20%) in Hcy-treated animals. Slight changes were noted in the ejection fraction, systolic fractional shortening, and maximal aortic valvular blood flow velocity, but they were not statistically significant or were similar to those in vehicle controls. The results suggest that an initial effect of Hcy administration involves loss of myocardial structure without a direct influence on myocardial contractile function. Consistent with this conclusion, in vitro evaluation of the myocardial ring contractile response showed no significant difference in left ventricular maximal isometric force between the control (13.9 +/- 2.7 g/g tissue) and Hcy-injected (11.0 +/- 2.8 g/g tissue) animals.