Prediction of Response to Cardiac Resynchronization Therapy: The Selection of Candidates for CRT (SCART) Study

Background: The aim of this study was to evaluate the ability of baseline clinical and echocardiographic parameters to predict a positive response to CRT.
Methods: We analyzed 6-month data from the first 133 consecutive patients enrolled in a multicenter prospective study. These patients had symptomatic heart failure (HF) refractory to pharmacological therapy (NYHA class II–IV), left ventricular ejection fraction (LVEF) ≤35%, and prespecified electrocardiographic, echocardiographic or tissue Doppler imaging markers of left ventricular (LV) dyssynchrony.
Results: After a follow-up period of 6 months, 1 patient died and 13 were hospitalized for worsening HF. There were significant (P < 0.01) clinical, functional, and echocardiographic improvements that included: New York heart Association Class, Quality-of-Life Score, QRS duration, LVEF, LV end-diastolic and end-systolic diameter (LVESD), and severity of mitral regurgitation A positive response was documented in 90/133 (68%) patients who presented an improved clinical composite score associated to an increase in LVEF ≥ 5 units. A multivariate analysis identified that a smaller LVESD (OR = 0.957, 95% CI 0.920–0.996; P = 0.030) and longer interventricular mechanical delay (IVMD) (OR = 1.017, 95% CI 1.005–1.029, P = 0.007) as independent predictors of a positive response. Receiver-operating curve analysis showed that a positive response to CRT may be predicted in patients with IVMD > 44 ms (with a sensitivity of 66% and a specificity of 55%) or with LVESD < 60 mm (with a sensitivity of 66% and a specificity of 61%).
Conclusions: Our results confirm the limited value of QRS duration in the selection of patients for CRT.
A less-advanced stage of disease and echocardiographic evidence of interventricular dyssynchrony demonstrated to predict response to CRT, while intraventricular dyssynchrony did not predict response.     

Left ventricular mechanical dispersion is associated with nonsustained ventricular tachycardia in hypertrophic cardiomyopathy

Objective: We assessed the value of speckle tracking two-dimensional (2D) strain echocardiography (2DSE) measured mechanical dispersion (MD) with other imaging and electrocardiographic parameters in differentiating hypertrophic cardiomyopathy (HCM) patients with and without nonsustained ventricular tachycardia (NSVT) on 24-h ambulatory ECG monitoring.

Methods and results: We studied 31 patients with HCM caused by the Finnish founder mutation MYBPC3-Q1061X and 20 control subjects with comprehensive 2DSE echocardiography and cardiac magnetic resonance imaging (CMRI). The presence of NSVT was assessed from ambulatory 24-h ECG monitoring.

NSVT episodes were recorded in 11 (35%) patients with HCM. MD was significantly higher in HCM patients with NSVT (93?±?41?ms) compared to HCM patients without NSVT (50?±?18?ms, p?=?0.012) and control subjects (41?±?16?ms, p?Conclusions: Increased mechanical dispersion was associated with NSVT in HCM patients on 24-h ambulatory ECG monitoring.

• Key messages

• The prediction of sudden cardiac death in hypertrophic cardiomyopathy remains a challenge and novel imaging methods are required to identify individuals at risk of malignant ventricular arrhythmias.

• Mechanical dispersion by speckle tracking echocardiography is associated with NSVT on 24-h ambulatory ECG monitoring in patients with hypertrophic cardiomyopathy

     

Late hyperenhancement in gadolinium-enhanced magnetic resonance imaging: comparison of hypertrophic cardiomyopathy patients with and without nonsustained ventricular tachycardia

Aim To assess the extent of hyperenhancement in hypertrophic cardiomyopathy (HCM) patients with nonsustained ventricular tachycardia (NSVT) in comparison to patients without NSVT. Design In HCM patients, NSVT in Holter monitoring is a risk factor for sudden cardiac death; however, its positive predictive value is low. Varying risk of sudden death related to NSVT may be dependent on the heterogeneous extent of the arrhythmogenic substrate, which seems to be visible as hyperenhancement in gadolinium-enhanced magnetic resonance imaging (MRI). Methods Hyperenhancement was assessed in 47 HCM patients (30 males and 17 females, mean age 42 ± 12 years): 32 patients had NSVT, 15 patients had no NSVT. The extent of hyperenhancement was calculated by software and expressed as a mass. Results In HCM patients with NSVT 97% had some extent of hyperenhancement on MRI, ranging from 1 to 76 g. The mean mass of hyperenhanced myocardium was 19 ± 18 g (8.1 ± 7.6% of total left ventricular mass). In HCM patients without NSVT, a significantly lower percentage of patients (60%) had hyperenhancement (P < 0.05). However, the amount of hyperenhanced myocardium was not significantly different (13 ± 19 g, 6.3 ± 9.1% of total left ventricular mass; P < 0.05). Conclusions Hyperenhancement was visible in almost all HCM patients with NSVT (97%) and in a significantly lower percentage of patients without NSVT (60%). Whether this finding explains the increased risk of sudden death in case of NSVT is not clear, since the extent of hyperenhancement was not significantly different between the two groups.     

Are Nonsustained Ventricular Tachycardias Predictive of Major Arrhythmias in Patients with Dilated Cardiomyopathy on Optimal Medical Treatment?

Background: To evaluate the role of nonsustained ventricular tachycardias (NSVT) for the prediction of major ventricular arrhythmias (MVA) in patients with idiopathic dilated cardiomyopathy (DCM) after optimization of medical treatment.
Methods and Results: Three hundred nineteen consecutive DCM patients were evaluated after adequate stabilization on optimal angiotensin-converting enzyme (ACE) inhibitor (88%) and β-blocker (82%) therapy. Frequency, length, and rate of NSVT at 24-hour Holter monitoring were analyzed to assess their values in predicting MVA (unexpected sudden death, SVT, ventricular fibrillation, and appropriate implantable cardioverter defibrillator interventions). During follow-up (median 96 months, 1^st–3^rd interquartile range 52–130), MVA incidence was low, and not statistically different between patients with and without NSVT (3 and 2 per 100 patient-years, respectively, P = nonsignificant [NS] at log-rank analysis). At multivariable analysis, the number of NSVT was predictive of MVA only if left ventricular ejection fraction (LVEF) was >0.35 (two NSVT/day vs no NSVT/day: hazard ratio [HR] 5.3, 95% confidence interval [CI] 1.59–17.85 in LVEF >0.35 vs HR 0.93, 95% CI 0.3–2.81 in LVEF ≤0.35). Consequently, in patients with LVEF ≤0.35, MVA incidence rates were similar regardless of NSVT (3.6 and 4.1 patient-years, respectively, in those with and without NSVT, P = NS), while in patients with LVEF >0.35, MVA incidence (3.1 per 100 patient-years vs 0.9 per 100 patient-years, P = 0.003) was significantly higher when NSVT were present.
Conclusions: After medical stabilization, NSVT did not increase the risk of MVA in patients with DCM and LVEF ≤0.35. Conversely, the number and length of NSVT runs were significantly related to the occurrence of MVA in the patients with LVEF >0.35.     

Measuring Quality of Care in Syncope: Case Definition Affects Reported Electrocardiogram Use but Does Not Bias Reporting

Objectives:  The objective was to calculate agreement between syncope as a reason for visiting (RFV) an emergency department (ED) and as a discharge diagnosis (International Classification of Diseases, Ninth Revision, Clinical Modification [ICD-9]), to determine whether syncope case definition biases reported electrocardiogram (ECG) usage, a national quality measure.
Methods:  The authors analyzed the ED portion of the National Hospital Ambulatory Medical Care Survey (NHAMCS), 1993–2004, for patients age ≥18 years. A visit was defined as being for syncope if it received one of three RFV or ICD-9 codes. Agreement between RFV and ICD-9 codes was calculated, and the percentages of syncope patients (RFV vs. ICD-9) who had an ECG were compared using chi-square and multivariate logistic regression.
Results:  Raw agreement between syncope as an RFV and as an ICD-9 diagnosis code was 30.1% (95% confidence interval [CI] = 32.6% to 35.5%), representing only moderate agreement beyond chance (κ = 0.50). ECG utilization was lower among visits defined by RFV (64.1%; 95% CI = 62.0% to 66.3%) than for ICD-9 diagnosis (73.6%; 95% CI = 71.4% to 75.8%). There was no meaningful variation in adjusted ECG use by patient, visit, or hospital characteristics between case definitions. Adjusted ECG use was lower under both case definitions among female patients and discharged patients and increased with age (p < 0.05).
Conclusions:  Despite only moderate agreement, syncope case definition should not bias reported ECG rate by patient, visit, or hospital characteristics. Among ED patients with syncope, ECG is performed less frequently in women, a potentially important disparity.     

Analysis of the Corrected QT Before the Onset of Nonsustained Ventricular Tachycardia in Patients with Hypertrophic Cardiomyopathy

BARANOWSKI, R., et al .: Analysis of the Corrected QT Before the Onset of Nonsustained Ventricular Tachycardia in Patients with Hypertrophic Cardiomyopathy. This study examined ventricular repolarization before the onset of 37 episodes of nonsustained ventricular tachycardia (NSVT) in 26 untreated patients with hypertrophic cardiomyopathy (HCM). Fourteen episodes were recorded in patients with a history of cardiac arrest or patients who died suddenly during follow-up. The QT interval was measured beat-by-beat on 24-hour ambulatory electrocardiograms. Mean 24-hour, hourly QTc and QTc of the last 10 beats prior to NSVT, consisted of 4–50 cycles (mean   9 ± 10   ), at the fastest rates of 100–175 beats/min (mean 122 ± 22) were analyzed. NSVT was more prevalent during nighttime (23 episodes), than during daytime (14 episodes,   P < 0.05   ). No significant differences were observed between mean 24-hour, mean hourly QTc during the hour with NSVT, and QTc of the last 10 cycles prior to onset of NSVT. QTc was significantly longer in patients with a history of sudden cardiac death (SCD) or who died suddenly during follow-up than in survivors. The 24-hour QT variability was higher in nonsurvivors than in survivors (   -39 ± 6   vs   33 ± 6 ms, P = 0.03   ). Episodes of NSVT in untreated patients with hypertrophic cardiomyopathy were more frequent during the nighttime. The 24-hour QT variability was higher in nonsurvivors than in survivors. (PACE 2003; 26[Pt. II]:387–389)     

Predictors of response to the head-up tilt test in patients with unexplained syncope or presyncope

BACKGROUND: Unexplained syncope is a relatively frequent symptom, mostly caused by a neurocardiogenic reaction. The purpose of this study was to determine predictors of response to head-up tilt testing (HUTT) in patients with unexplained syncope or presyncope. METHODS: HUTT was done in 640 consecutive patients with unexplained syncope or presyncope (393 men, mean age 45+/-19 years) after initial workup including history, physical examination, and appropriate laboratory evaluation. RESULTS: Three hundred and forty-four (54%) patients had a positive result. The most common type of response was mixed type (46%) followed by vasodepressor (39%) and cardioinhibitory (15%) types. Age, gender, presence of structural heart disease, baseline heart rhythm, and the presenting symptom before the test failed to predict a positive response to HUTT, but among patients with a positive response to the test, age (OR: 1.54, CI = 1.04-2.47, P = 0.016) and presyncope (OR: 2.16, CI = 1.2-3.85, P = 0.008) as the presenting symptom predicted a vasodepressor type of response. The age (OR: 1.58, CI = 1.29-3.94, P = 0.01) and presyncope (OR: 4.6, CI = 1.74-12.24, P = 0.001) were also predictors for test positivity in the active stage. CONCLUSIONS: There is an age-related gradient in hemodynamic response during neurocardiogenic syncope. The elderly patients more commonly had a vasodepressor and late response, in the active stage, but young subjects more commonly experienced an earlier and cardioinhibitory or mixed responses in the passive stage.     

Ventricular Arrhythmia Factors in Mitral Valve Prolapse

To assess tbe prevalence of ventricular arrhythmias and late potentials (LPs) in mitral valve prolapse (MVP) and to identify clinical, ECG, and echocardiographic markers of spontaneous ventricular arrhythmias, we studied 58 consecutive patients (mean age 46.6 ± 17.8 years; 29 males, 29 females) with MVP diagnosed by echocardiography. Patients underwent ambulatory ECG recording (n = 58), exercise stress test (n = 56), signal-averaged ECG (n = 58), and programmed ventricular stimulation (n = 52). Ten patients (17.2%) had spontaneous nonsustained ventricular tachycardia (NSVT), 26 patients (44.8%) had premature ventricular contractions (PVGs), Lown grade ≥ 3 during 24-hour EGG, and 19 had Lown grade ≥ 3 PVCs during exercise stress test; 13 patients had LPs (22.4%). We provoked sustained VT in one case and NSVT in ten cases. Patients with complex ventricular arrhythmias during 24-hour EGG and exercise stress test were older and more often had mitral regurgitation. There was a statistical correlation between the presence of LPs and spontaneous VT (46.1 % vs 8.9%; P < 0.005) and induced ventricular arrhythmias (50% vs 12.8%; P < 0.005). No correlation was found between spontaneous ventricular arrhythmias and thickness or posterior displacement of the mitral valve. In conclusion, complex ventricular arrhythmia (especially VT) and LPs are frequent in MVP. Patient age and mitral regurgitation seem to be determinant factors of complex ventricular arrhythmias in MVP. On signal-averaged EGG, absence of LPs seems to be a good additional marker to identify MVP patients without spontaneous VT. On the other hand, programmed ventricular stimulation does not appear valuable in determining a MVP subgroup with a high risk of ventricular arrhythmias.     

Correlates of patient acceptance of the cardioverter defibrillator: cross-validation of the Florida Patient Acceptance Survey in Danish patients

Background: Device acceptance may comprise one of the keys to identifying implantable cardioverter defibrillator (ICD) patients at risk for adverse health outcomes in clinical practice. We examined (1) the validity and reliability of the Florida Patient Acceptance Survey (FPAS) and (2) correlates of device acceptance in a large sample of Danish patients.
Methods: A cohort of consecutive patients (N = 566; 82.2% males; mean age = 61.9 ± 14.3) implanted with an ICD since 1989 and still alive on November 1, 2006, completed a set of psychological questionnaires.
Results: The four-factor structure and the validity of the FPAS were confirmed, with the four factors accounting for 64.3% of the variance. The reliability, measured by Cronbach's α, was acceptable for the total scale and all subscales, ranging from 0.73 to 0.85. Correlates of poor device acceptance included older age (OR: 1.03; 95% CI: 1.01–1.05), symptomatic heart failure (OR: 3.59; 95% CI: 2.12–6.08), Type D personality (OR: 3.51; 95% CI: 1.95–6.30), anxiety (OR: 2.33; 95% CI: 1.24–4.38), depressive symptoms (OR: 2.24; 95% CI: 1.00–5.00), and ICD concerns (OR: 4.16; 95% CI: 2.55–6.80); having a partner was associated with better acceptance (OR: 0.53; 95% CI: 0.31–0.91), adjusting for demographic and clinical factors including shocks. Shocks were not associated with outcome (P = 0.59).
Conclusions: The FPAS was shown to be a valid and reliable measure of device acceptance in a large sample of Danish ICD patients. Psychological factors rather than clinical factors were the primary correlates of poor device acceptance, whereas having a partner was associated with better acceptance. These preliminary findings suggest that screening for psychological factors may aid clinicians in identifying patients at risk of poor device acceptance.     

Long Runs of Non-Sustained Ventricular Tachycardia on 24-Hour Ambulatory Electrocardiogram Predict Major Arrhythmic Events in Patients with Idiopathic Dilated Cardiomyopathy

This study examined the prognostic significance of the rate and length of non-sustained (NS) ventricular tachycardia (VT) on 24-hour ambulatory electrocardiograms (ECG) recorded in 343 patients with idiopathic dilated cardiomyopathy (IDC) in the prospective Marburg Cardiomyopathy study. NSVT was defined as ≥3 consecutive ventricular premature beats at >120 bpm. During 52 ± 21 months of follow-up, major arrhythmic events defined as sustained VT, VF, or sudden cardiac death occurred in 46 of 343 patients (13%). Patients with 3–4 beat runs of NSVT had a similar arrhythmia-free survival as patients without NSVT on baseline 24-hour ambulatory ECG. The incidence of major arrhythmic events during follow-up increased significantly from 2% per year in patients without NSVT, to 5% per year in patients with 5–9 beat runs of NSVT, to 10% per year in patients with ≥10 beat runs of NSVT (P < 0.05). Unlike the length, the rate of NSVT was similar in patients with versus without subsequent major arrhythmic events (163 ± 23 vs 160 ± 24 bpm). Thus, the length but not the rate of NSVT on 24-hour ambulatory ECG was a predictor of major arrhythmic events in patients with IDC. The presence of NSVT with ≥10 beat runs on ambulatory ECG was associated with a particularly high risk of major arrhythmic events.     

Multicenter Study of Limited Health Literacy in Emergency Department Patients

Objectives:  The objective was to evaluate the prevalence of limited health literacy and its association with sociodemographic variables in emergency department (ED) patients.
Methods:  This was a cross-sectional survey in three Boston EDs. The authors enrolled consecutive adult patients during two 24-hour periods at each site. They measured health literacy by the short version of the Test of Functional Health Literacy in Adults (S-TOFHLA). Using multivariate logistic regression, the authors evaluated associations between sociodemographic variables and limited health literacy, as classified by S-TOFHLA scores.
Results:  The authors enrolled 300 patients (77% of eligible). Overall, 75 (25%; 95% confidence interval [CI] = 20% to 30%) of participants had limited health literacy. Limited health literacy was independently associated with older age (compared to 18–44 years, odds ratio [OR] 4.3 [95% CI = 2.0 to 9.2] for 45–64 years and OR 3.4 [95% CI = 1.4 to 8.5] for ≥65 years), less education (compared to high school graduates, OR 2.7 [95% CI = 1.1 to 7.3] for some high school or lower and OR 0.43 [95% CI = 0.21 to 0.88] for some college or higher), and lower income (OR 2.8 [95% CI = 1.2 to 6.6] for ≤$40,000 compared to >$40,000). Although ethnicity, race, and language were associated with limited health literacy in unadjusted analyses, the associations were not significant on multivariate analysis.
Conclusions:  In this sample, one-quarter of ED patients would be expected to have difficulty understanding health materials and following prescribed treatment regimens. Advanced age and low socioeconomic status were independently associated with limited health literacy. The ability of a significant subgroup of ED patients to understand health information, especially during illness or injury, requires further study.     

Multicenter Validation of the Philadelphia EMS Admission Rule (PEAR) to Predict Hospital Admission in Adult Patients Using Out-of-hospital Data

Objectives:  The objective was to validate a previously derived prediction rule for hospital admission using routinely collected out-of-hospital information.
Methods:  The authors performed a multicenter retrospective cohort study of 1,500 randomly selected, adult patients transported to six separate emergency departments (EDs; three community and three academic hospitals in three separate health systems) by a city-run emergency medical services (EMS) system over a 1-year period. Patients younger than 18 years or who bypassed the ED to be evaluated by trauma, obstetric, or psychiatric teams were excluded. The score consisted of six weighted elements that generated a total score (0–14): age ≥ 60 years (3 points); chest pain (3); shortness of breath (3); dizzy, weakness, or syncope (2); history of cancer (2); and history of diabetes (1). Receiver operator characteristic (ROC) curves for the decision rule and admission rates were calculated among individual hospitals and for the entire cohort.
Results:  A total of 1,102 patients met inclusion criteria. The admission rate for the entire cohort was 40%, and individual hospital admission rates ranged from 28% to 57%. Overall, 34% had a score of ≥4, and 29% had a score of ≥5. Area under the ROC curve (AUC) for the combined cohort was 0.83 for all admissions and 0.72 for intensive care unit (ICU) admissions; AUCs at individual hospitals ranged from 0.72 to 0.85. The admission rate for a score of ≥4 was 77%; for a score of ≥5 the admission rate was 80%.
Conclusions:  The ability of this EMS rule to predict the likelihood of hospital admission appears valid in this multicenter cohort. Further studies are needed to measure the impact and feasibility of using this rule to guide decision-making.     

T Wave Complexity in Patients with Hypertrophic Cardiomyopathy

The complexity of the T wave assessed by principal component analysis (PCA) has been proposed to reflect obnormal repolarization, which may be arrhythmogenic. To determine whether PCA can differentiate patients with hypertrophic cardiomyopathy (HCM) from normal subfects and whether PCA is of prognostic importance in HCM, 112 patients with HCM (41 ±14 years, 64 males) and 72 healthy subjects (39 ± 9 years, 41 males) were studied. Patients with sinus node dysfunction, AV conduction block, flat T waves, QRS > 140 ms, and those < 15 years were excluded from this study. Standard 12-lead ECGs were recorded digitally using the MAC-VU system (Marquette Medical Systems). PCA parameters were computed using the QT Guard software package by Marquette. PCA ratio was significantly greater in HCM patients than in normal controls (23.9%± 12.4% vs 16.1%± 7.6%, P < 0.0001) and was correlated with QT-end dispersion (r = 0.24. P = 0.01) and QT peak (Q point to T peak) dispersion (r = 0.35, P < 0.0001). HCM patients with syncope (n = 23) had increased PCA ratios compared with those without syncope (29.1%± 11.5% vs 22.5%± 12.3%, P = 0.01). PCA ratio was similar in patients with and without nonsustained ventricular tachycardia on Holter (25.9%± 11.4% vs 22.7%± 12.1%, P = 0.2), as well as in patients treated with amiodarone or sotalol versus those not on therapy. In conclusion, assessment of the complexity of the T wave by PCA differentiates HCM patients from normal subjects. PCA ratio correlated with QT dispersion and an increased PCA ratio was associated with a history of syncope in HCM.     

Long-Term Survival in Patients Treated with Cardiac Resynchronization Therapy: A 3-Year Follow-Up Study from the InSync/InSync ICD Italian Registry

Background: Studies reporting the long-term survival of patients treated with cardiac resynchronization therapy (CRT) outside the realm of randomized controlled trials are still lacking. The aim of this study was to quantify the survival of patients treated with CRT in clinical practice and to investigate the long-term effects of CRT on clinical status and echocardiographic parameters.
Methods: The study population consisted of 317 consecutive patients with implanted CRT devices from eight Italian University/Teaching Hospitals. The patients were enrolled in a national observational registry and had a minimum follow-up of 2 years. A visit was performed in surviving patients and mortality data were obtained by hospital file review or direct telephone contact.
Results: During the study period, 83 (26%) patients died. The rate of all-cause mortality was significantly higher in ischemic than nonischemic patients (14% vs 8%, P = 0.002). Multivariate analysis showed that ischemic etiology (HR 1.72, CI 1.06–2.79; P = 0.028) and New York Heart Association (NYHA) class IV (HR 2.87, CI 1.24–6.64; P = 0.014) were the strongest predictors of all-cause mortality. The effects of CRT persisted at long-term follow-up (for at least 2 years) in terms of NYHA class improvement, increase of left ventricular ejection fraction, decrease of QRS duration (all P = 0.0001), and reduction of left ventricular end-diastolic and end-systolic diameters (P = 0.024 and P = 0.011, respectively).
Conclusions: During long-term (3 years) follow-up after CRT, total mortality rate was 10%/year. The outcome of ischemic patients was worse mainly due to a higher rate of death from progressive heart failure. Ischemic etiology along with NYHA class IV was identified as predictors of death. Benefits of CRT in terms of clinical function and echocardiographic parameters persisted at the time of long-term follow-up.     

Predictive Value of Repeated Versus Single N-Terminal Pro B-Type Natriuretic Peptide Measurements Early After-Myocardial Infarction

Background: A single, markedly elevated B-type natriuretic peptide (BNP) serum concentration predicts an increased risk of death after myocardial infarction (MI), though its sensitivity and predictive accuracy are low. We compared the predictive value of a modestly and persistently elevated, versus a single, markedly elevated measurement of N terminal pro-BNP (NT-BNP) early after MI.
Methods and Results: NT-BNP was measured 2–4, 6–10, and 14–18 weeks after MI. The median age of the 100 patients was 61 years, median left ventricular ejection fraction (LVEF) was 0.40, and 88% were males. Over a median follow-up of 39 months, 10 patients died. The initial median NT-BNP was 802 pg/mL and declined over time (P = 0.002). An initial NT-BNP ≥2,300 pg/mL (upper quintile) was observed in 19 patients and predicted a 3.4-fold higher independent risk of death (P = 0.05), with modest sensitivity (30%) and positive predictive accuracy (16%). A NT-BNP consistently ≥1,200 pg/mL (upper tertile) was observed in 19 patients, and was associated with a 5.7-fold higher independent risk of death (P = 0.01), with a higher sensitivity (50%) and positive predictive accuracy (26%) than a single, markedly elevated NT-BNP measurement.
Conclusions: A moderately and persistently elevated NT-BNP in the early post-MI period was associated with a 5.7-fold higher risk of death, independent of age, LVEF, and functional class. Compared with a single measurement, serial NT-BNP measurements early after MI were more accurate predictors of risk of death.     

Identifying False-positive ST-elevation Myocardial Infarction in Emergency Department Patients

Background

In a push to treat ST-elevation myocardial infarction (STEMI) patients with primary percutaneous coronary intervention (PCI) within 90 min of door-to-balloon time, emergency cardiac catheterization laboratory activation protocols bypass routine clinical assessments, raising the possibility of more frequent catheterizations in patients with no culprit coronary lesion.

Objective

To determine the incidence, predictors, and prognosis of false-positive STEMI.

Methods

We followed a prospective cohort of patients diagnosed with STEMI by usual criteria receiving emergency cardiac catheterization with intention of primary PCI between January 2005 and December 2007 at a tertiary care center. False-positive STEMI was defined as absence of a clear culprit lesion on coronary angiography.

Results

Of 489 patients who received emergency cardiac catheterization indicated for STEMI, 54 (11.0%, 95% confidence interval [CI] 8.3–13.8) had no culprit lesion on coronary angiography. Independent predictors of false-positive STEMI were absence of chest pain (odds ratio [OR] 18.2, 95% CI 3.7–90.1), no reciprocal ST-segment changes (OR 11.8, 95% CI 5.14–27.3), fewer than three cardiovascular risk factors (OR 9.79, 95% CI 4.0–23.8), and symptom duration longer than 6 h (OR 9.2, 95% CI 3.6–23.7); all p < 0.001. Using predictors, we modeled a risk score that achieved 88% (95% CI 81–94%) accuracy in identifying patients with negative coronary angiography. Among the false-positive STEMI patients, 48.1% had other serious diagnoses related to their electrocardiographic findings.

Conclusion

When the diagnosis of STEMI is in doubt, clinicians may use predictors to quickly reassess the likelihood of an alternative diagnosis.     

Does Familiarity with Technology Predict Successful Use of an External Loop Recorder? The Loop Recorder Technology Cognition Study (LOCO)

Background: The diagnosis of presyncope, syncope, and palpitations is facilitated by successful documentation of the cardiac rhythm during symptoms. We prospectively assessed technological familiarity using a Technology Cognition Questionnaire to determine influence on proper and effective use of an external loop recorder (ELR).
Methods: Patients with palpitations, presyncope, or syncope were assessed for familiarity with technology and provided an ELR for a period of 6 weeks. Proper use of the device was demonstrated to the patient and test transmissions were sent by analog telephone line on a weekly basis. Patients were instructed to activate the device to record cardiac rhythm when symptoms recurred, and to send these recordings via telephone transmission.
Results: Ninety-two patients were prospectively enrolled, with mean age 54.9 ± 20.9 and 42 males (46%). Sixty-five patients (71%) had recurrence of symptoms during the 6-week monitoring period. Among these patients, 40 (62%) were successful in recording and transmitting data such that a diagnosis was made at a median of 8 days (IQR 12.5, range 0–30). Among patients with symptoms during the monitoring period, 36 (55%) had at least one failed recording or transmission. On multivariate analysis, failed symptom recording/transmission was less likely among patients able to program a home video recorder (odds ratio [OR] 0.25 [0.07–0.93]), and more likely among patients who failed a test transmission (OR 3.45 [1.04–11.7]). No variables were independently associated with successful diagnosis.
Conclusions: Familiarity with technology correlates with successful use of the ELR, but does not necessarily correlate with the ability to reach a diagnosis.     

Demographic Factors and Their Association with Outcomes in Pediatric Submersion Injury

Objectives: To describe the epidemiology and outcomes of serious pediatric submersion injuries and to identify factors associated with an increased risk of death or chronic disability.
Methods: A retrospective database review of 1994–2000 Massachusetts death and hospital discharge data characterized demographic factors; International Classification of Diseases, Ninth Revision (ICD-9), Clinical Modification (ICD-9-CM), or ICD-10 injury codes; and outcomes for state residents 0–19 years of age identified with unintentional submersion injuries. The authors performed logistic regression analysis to correlate outcomes with risk and demographic factors.
Results: The database included 267 cases of serious submersion injury, defined as those requiring hospitalization or leading to death. Of these 267 patients, 125 (47%) drowned, 118 (44%) were discharged home, 13 (5%) were discharged home with intravenous therapy or with availability of a home health aide, and 11 (4%) were discharged to an intermediate care/chronic care facility. The authors observed a trend of improved outcome in successively younger age groups (p < 0.0001). The multivariable logistic regression analysis showed an increased likelihood of poor outcome for males compared with females (odds ratio [OR]: 2.52; 95% confidence interval [95% CI] = 1.31 to 4.84) and for African Americans compared with whites (OR: 3.47; 95% CI = 1.24 to 9.75), and a decreased likelihood of poor outcome for Hispanics compared with whites (OR: 0.056; 95% CI = 0.013 to 0.24).
Conclusions: After serious pediatric submersion injuries, the overall outcome appears largely bimodal, with children primarily discharged home or dying. The observations that better outcomes occurred among younger age groups, females, and Hispanic children, with worse outcomes in African American children, suggest that injury prevention for submersion injuries should consider differences in age, gender, and race/ethnicity.     

Gender Differences in Anxiety and Concerns about the Cardioverter Defibrillator

Background: Little is known about gender differences in the response to implantable cardioverter defibrillator (ICD) therapy. We compared female and male ICD patients on anxiety, depression, health-related quality of life (HRQL), ICD concerns, and ICD acceptance.
Methods: A cohort of consecutive, surviving patients (n = 535; mean age = 61.5 ± 14.4, 81.9% male) implanted with an ICD between 1989 and 2006 completed the Hospital Anxiety and Depression Scale, the Short-Form Health Survey (SF-36), the ICD concerns questionnaire, and the Florida Patient Acceptance Survey.
Results: High levels of anxiety (52% vs 34%, P < 0.001) and ICD concerns (34% vs 16%, P = 0.001) were more prevalent in women than men, whereas no significant differences were found on depression and device acceptance (Ps > 0.05). Women were more anxious (odds ratio [OR]: 2.60 [95% confidence interval (CI): 1.46–4.64], P < 0.01) and had more ICD concerns (OR: 1.81 [95% CI: 1.09–3.00], P < 0.05) than men, adjusting for demographic and clinical characteristics. Those ICD patients experiencing shocks were also more anxious (OR: 2.02 [95% CI: 1.20–3.42], P < 0.01) and had higher levels of ICD concerns (OR: 2.70 [95% CI: 1.76–4.16], P < 0.01). In multivariable analysis of variance, significant gender differences were found for only three of the eight subscales of the SF-36 (the physical social functioning and the mental health subscale), with women reporting poorer HRQL on all three subscales.
Conclusions: Women were more prone to experience anxiety and ICD concerns compared to men regardless of whether they had experienced shocks. In clinical practice, female ICD patients should be closely monitored, and if warranted offered psychosocial intervention, as increased anxiety has been shown to precipitate arrhythmic events in defibrillator patients.