Cardiovascular Complaints Among Military Members During Operation Enduring Freedom.

During Operation Enduring Freedom, the US military began deploying a dedicated theater cardiology consultant to Afghanistan in an effort to increase rates of return to duty in service members with cardiovascular complaints. This study was designed to categorize these complaints and determine the effect on both aeromedical evacuation and return to duty rates during a 2.5 year observation period. A total of 1,495 service members were evaluated, with 43% presenting due to chest pain followed by arrhythmias/palpitations (24.5%) and syncope (13.5%). Eighty-five percent of individuals returned to duty, most commonly with complaints of noncardiac chest pain, palpitations, or abnormal electrocardiograms. Fifteen percent were evacuated out of theater, most often with acute coronary syndrome, pulmonary embolus, or ventricular tachycardia. The forward-deployed theater cardiology consultant is vital in the disposition of military members by effectively parsing out life threatening cardiovascular conditions versus low risk diagnoses that can safely return to duty.

The effects of body mass index on surface electrocardiograms in young adults.

INTRODUCTION: While BMI is known to affect ECG measurements, these effects have not been well characterized in young adults. METHODS: We retrospectively reviewed all ECGs performed in adults 18 to 35 years old at a single institution over a 30 year period. ECG measurements were derived electronically and stratified by WHO BMI category. RESULTS: A total of 55,218 ECGs were included. Increasing BMI led to increased P wave duration and decreasing P, R, and T wave axes. Additionally, while increasing BMI led to less R wave voltage, J point elevation, and T wave amplitude in patients with a BMI ≥ 18.5 kg/m(2), there was also a decrease in the measured parameters in patients with a BMI <18.5 kg/m(2). DISCUSSION: BMI had significant effects on ECG measurements. For accurate assessment of ECGs, these data should be incorporated into established nomograms. Further investigation into the effects of BMI on the ECG is warranted.

Long-term mortality after transvenous lead extraction.

BACKGROUND: The number of cardiovascular implantable electronic devices has increased progressively and has led to an increased need for transvenous lead extraction (TLE). Multiple reports of TLE procedural outcomes exist; however, data regarding postprocedural and long-term mortality are limited. METHODS AND RESULTS: We performed a retrospective study of consecutive patients undergoing TLE at a single, high-volume center. Patient characteristics, indications, and outcomes were analyzed. A multivariable Cox regression model was developed to identify factors associated with mortality. Between January 2000 and December 2010, 985 patients underwent 1043 TLE procedures. The cohort was 68% male, with a mean age of 63 years (range, 15-95 years) and a left ventricular ejection fraction of 40±17%. Indications included systemic infection (18%), pocket infection (32%), lead malfunction (30%), and other (device upgrade, venous occlusion, and advisory leads; 20%). There were no procedure-related deaths. The mean follow-up was 3.7 years (range, 0.1-11.3 years). Kaplan-Meier analysis demonstrated a cumulative mortality of 2.1% at 30 days, 4.2% at 3 months, 8.4% at 1 year, and 46.8% at 10 years. In multivariable analysis, systemic infection (hazard ratio [HR], 3.52; 95% CI, 1.95-6.38; P<0.0001), local infection (HR, 2.70; 95% CI, 1.55-4.67; P=0.0004), device system upgrade (HR, 2.14; 95% CI, 1.07-4.25; P=0.03; indication compared with a reference group of extraction for lead malfunction), diabetes mellitus (HR, 1.71; 95% CI, 1.25-2.35; P=0.0009), increasing age (HR, 1.05; 95% CI, 1.04-1.07; P<0.0001), and serum creatinine (HR, 1.16; 95% CI, 1.01-1.35; P=0.04) were significant correlates of increased mortality risk. CONCLUSIONS: Although TLE procedural mortality is exceedingly low at high-volume centers, postprocedural and long-term mortality remain high in certain patient populations, such as elderly patients and those undergoing TLE for infectious indications and device system upgrade. Information regarding TLE long-term outcomes may help guide cardiovascular implantable electronic device and lead management.

Effects of glucosamine and Celadrin on platelet function.

OBJECTIVE: The purpose of this study was to determine the effects of glucosamine and celadrin on platelet function. DESIGN: Baseline values were determined on the Chronolog 570VS platelet aggregometer with whole blood aggregation impedance readings using 2 different concentrations of ADP (5 microM, 10 microM), collagen (1 microg/mL), arachidonic acid (0.5 mM/L) and an Accumetrics whole blood platelet aggregation cartridge assay for P2Y12 receptors were obtained from 24 healthy volunteers. These subjects then took the suggested doses of Glucosamine with Celadrin (Stockbridge Naturals) as advertised (estimated 1500mg daily) for 2 weeks. Platelet aggregation analyses, as described above, were obtained after treatment. Statistics performed via a McNemar test. MAIN OUTCOME: Five of twenty-four subjects had at least a 20% difference in whole blood aggregation using the 5 microM concentration of ADP. A total of 6 and 7 subjects also showed a significant difference in platelet aggregation with administration of collagen and arachidonic acid, respectively. No significant differences were found with Accumetrics assay for P2Y12 in any of the subjects. CONCLUSION: Glucosamine and celadrin may inhibit platelet aggregation in some individuals via aspirin-like effects as well as inhibition of ADP receptor P2Y1 but not P2Y12.

Large, single-center, single-operator experience with transvenous lead extraction: outcomes and changing indications.

BACKGROUND: Lead extraction is increasingly necessary given the exponential growth in cardiac device implantation. Meanwhile, the tools, indications, and outcomes of this procedure continue to change. OBJECTIVE: The purpose of this study was to examine contemporary indications, outcomes, and complications of transvenous lead extraction in a large series of patients at a high-volume lead extraction center. METHODS: We performed a retrospective cohort study of consecutive patients undergoing lead extraction at a single, high-volume center. Patient and lead characteristics and the indications, outcomes, and need for laser assistance were analyzed. RESULTS: From January 2000 to March 2007, a total of 975 chronic endovascular leads were removed from 498 patients. Median implant duration was 5.7 years (range 0.5-32.7 years). Indications were infection (60.3%), mechanical lead failure (29.3%), and upgrade of device system (8.8%). Over the study period, lead malfunction decreased relative to other indications. Laser assistance for extraction was more likely with leads implanted longer than 3.4 years compared to less than 3.4 years (odds ratio 6.15, 95% confidence interval 3.35-11.28) and with implantable cardioverter-defibrillator leads compared to pacemaker leads (odds ratio 3.44, 95% confidence interval 1.84-6.43). Overall, 97.5% of the leads were completely removed. Major complications occurred in 2 (0.4%) patients. Only one patient required cardiac surgery. No deaths occurred. CONCLUSION: In a high-volume center, lead extraction has a high success rate and low complication rate. Infection was the most common indication overall. Lead failure has decreased in relative proportion. Implantable cardioverter-defibrillator leads and longer lead implant time are associated with a requirement for laser lead extraction.

Chronic atrial fibrillation ablation impact on endocrine and mechanical cardiac functions.

AIMS: Assess the impact of persistent/permanent atrial fibrillation (AF) ablation on endocrine and mechanical cardiac functions. METHODS AND RESULTS: In all, 43 patients (40 males, 53 +/- 12 years) undergoing persistent/permanent AF ablation had atrial (ANP) and brain natriuretic peptide (BNP) measurements before day 1, 3, and 3 months after ablation. In the same period of time transthoracic echocardiography was performed. With a mean radiofrequency delivery of 98 +/- 29 min, sinus rhythm (SR) was restored in 30 patients (70%) without DC shock. ANP decreased significantly (P < 0.001) with restoration of SR and then increased until day 3 post ablation without reaching the level observed during AF. At 3 months, ANP was significantly lower than day 3 reaching normal value in 28 (65%) patients and being <7 pg/mL in 4 (9%). The BNP followed the same trend with normal BNP level in 23 (53%) patients at 3 months. Identifiable atrial filling waves on the pulsed Doppler transmitral recordings performed between day 2 and day 4 after the procedure were seen in 18 patients (42%). At 3 months, 39 (95%) of the patients with SR during echocardiography had a significant A wave. CONCLUSION: SR following persistent/permanent AF ablation is associated with a dramatic decrease in natriuretic peptides. At 3 months, despite relatively extensive atrial ablation, endocrine and mechanical cardiac functions are significantly improved.

Direct admission to cardiology for patients hospitalized for atrial fibrillation reduces length of stay and increases guideline adherence.

OBJECTIVE: We hypothesized that a clinical pathway for inpatient management of atrial fibrillation on a cardiology service would result in improved resource utilization. METHODS: In July 2002, an evidence-based pathway was developed for treatment of patients hospitalized for atrial fibrillation. Guidelines directed patient care from admission from the emergency department to inpatient management on a cardiology service. Ancillary testing, anticoagulation, and inpatient length of stay were then compared before and after institution of the pathway. RESULTS: The overall length of stay was significantly shorter for patients admitted through the pathway (43.0 hours vs. 82.0 hours, p < 0.01). After the pathway, there was increased use of transesophageal echocardiography and a trend toward increased use of warfarin. CONCLUSIONS: Patients requiring hospitalization for symptomatic atrial fibrillation had a nearly 50% reduction in length of stay, with a trend toward increased utilization of risk-appropriate antithrombotic therapy, if they were directly admitted through cardiology via a clinical pathway.

Sudden death associated with anomalous coronary origin and obstructive coronary disease in the young.

Sudden cardiac death in a young patient is a catastrophic occurrence. Anomalous coronary origin (ACO) is a significant cause of sudden cardiac death among individuals under the age of 35 years. We sought to define the premortem clinical and postmortem histopathologic findings in victims of sudden cardiac death resulting from either ACO or obstructive atherosclerotic coronary artery disease (CAD) among U.S. military recruits (ages 17-35 years). The autopsy records of all sudden cardiac deaths occurring among recruits during their basic military training period from 1977 through 2001 were reviewed. Twenty-one deaths were associated with ACO and 10 with CAD. Recruits with ACO were more likely to have prodromal symptoms of exertional syncope and/or chest pain (48% vs. 0%, P = 0.011). All sudden cardiac deaths resulting from ACO involved a left main coronary artery takeoff from the right coronary sinus with a course between the aorta and the right ventricular outflow tract and an otherwise normal distribution of the major epicardial coronary arteries. Myocardial fibrosis was seen equally in those with both CAD and ACO (30% vs. 20%, P = 0.66), but the finding of necrosis tended to be more common among recruits with CAD (50% vs. 15%, P = 0.08). In conclusion, review of autopsy data of sudden cardiac deaths among U.S. military recruits reveals myocardial fibrosis or necrosis occurred in 70% of cases with CAD and 35% of cases with ACO. Sudden cardiac deaths resulting from ACO were more likely to be associated with premortem exertional chest discomfort and/or syncope compared with deaths resulting from CAD.

Comparison of clinical presentation of acute myocarditis following smallpox vaccination to acute coronary syndromes in patients <40 years of age.

Smallpox vaccine-associated myopericarditis may have a similar presentation to acute coronary syndrome (ACS). The clinical records of 78 young patients (<40 years of age) presenting with ACS (n = 16) or myocarditis after smallpox vaccination (n = 62) were reviewed. Comparisons were made among clinical presentation, cardiac enzymes, echocardiographic findings, and electrocardiographic changes. The presence of cardiac risk factors or focal wall motion abnormalities on echocardiography were associated with a diagnosis of ACS. There was a trend toward earlier elevation of troponin-I and creatine kinase in patients with myocarditis compared with ACS.

Review of subacute stent thrombosis following percutaneous coronary intervention at a low-volume catheterization laboratory.

BACKGROUND: The frequency of coronary stent subacute thrombosis (SAT) following percutaneous coronary intervention (PCI) with uncoated stents in recent studies is 0.5%-0.9%. Prior studies have indicated that complication rates are significantly higher when performed in low-volume centers. We sought to determine the incidence and outcomes of SAT following PCI with stent placement at a low-volume catheterization laboratory. METHODS: We reviewed the Brooke Army Medical Center Interventional Database for all consecutive PCIs with stent implantation performed from January 1998 to December 2002. Clinical outcomes were obtained primarily through hospitalization records and clinic follow-up visits. RESULTS: There were 789 interventions with stenting on 750 patients over the specified time period, for an average of 158 procedures on 150 patients per year. There were seven cases of SAT, representing a rate of 0.89%. There was no difference in the clinical characteristics, procedural technique, or postprocedural antithrombotic therapy of the subjects with and without SAT. Of those with SAT, there were no subjects requiring surgical revascularization during index hospitalization, and all survived to index hospital discharge. Six of these seven subjects with SAT (85.7%) were alive at one year, with the single death noncardiovascular related. CONCLUSIONS: The incidence of thrombosis occurring within 30 days of intracoronary stent implantation is similar in low- and high-volume catheterization laboratories. In our low-volume laboratory experience, these events were not associated with significantly increased adverse outcomes.