Feasibility of an exercise intervention for fatigued breast cancer patients at a community-based cardiac rehabilitation program.

PURPOSE: Exercise is beneficial to quality of life after cancer treatment, yet few cancer survivors meet exercise guidelines. Our study sought to determine the feasibility of an oncology rehabilitation exercise program embedded within a cardiac rehabilitation program. METHODS: Patients who rated their fatigue >4/10 after completion of adjuvant chemotherapy for breast cancer were screened for eligibility and the outcomes were assessed (Piper Fatigue Scale, Functional Assessment of Cancer Therapy-Breast [FACT-B], Edmonton Symptom Assessment System, body composition, stress test, and physical activity measurement [accelerometer]). Participants received individualized exercise prescription. Following the 16-week program, repeat assessment plus patient acceptance and satisfaction survey was completed. The primary end point was the composite of accrual rate >25%, program adherence >80%, and mean compliance with accelerometer use >80%. RESULTS: Twenty of 24 screened patients consented to the study and completed the baseline assessment. Adherence was 30.3%. Mean accelerometer use was 3.88/7 days (78%). Fatigue at baseline was rated at 4.82/10, and at 3.59 (p = 0.09) after the intervention. Overall well-being (FACT-B) score changed from 92.7 to 98.3 (p = 0.05). There were no significant changes in body composition (except for bone mineral content), aerobic exercise capacity, or activity patterns. CONCLUSION: Although the primary outcome was not met, our study indicates that an oncology exercise rehabilitation program can be incorporated into an existing cardiac rehabilitation program. Based on feedback received, we propose that in order to achieve exercise goals, frequent, encouraging, and tailored feedback and group sessions to foster a sense of community may additionally be needed to strengthen adherence to a prescribed exercise program.

Very high coronary artery calcium score with normal myocardial perfusion SPECT imaging is associated with a moderate incidence of severe coronary artery disease.

PURPOSE: Myocardial perfusion imaging (MPI) has limitations in the presence of balanced multivessel disease (MVD) and left main (LM) coronary artery disease, occasionally resulting in false-normal results despite the high cardiovascular risk associated with this condition. The purpose of this study was to assess the incidence of severe coronary artery disease (CAD) in the presence of a very high Agatston coronary artery calcium (CAC) score (>1,000) in stable symptomatic patients without known CAD but with normal MPI results. METHODS: A total of 2,659 prospectively acquired consecutive patients were referred for MPI and evaluation of CAC score by CT. Of this patient population, 8 % (222/2,659) had ischemia without myocardial infarction (MI) on MPIand 11 % (298/2,659) had abnormal MPI (MI and/or ischemia). On presentation 1 % of the patients (26/2,659) were symptomatic, had a CAC score >1,000 and normal MPI results. The definition of normal MPI was strict and included a normal hemodynamic response without ischemic ECG changes and normal imaging, particularly absence of transient ischemic dilation. All of these 26 patients with a CAC score >1,000 and normal MPI findings underwent cardiac catheterization. RESULTS: Of these 26 patients, 58 % (15/26) had severe disease (≥70 % stenosis) leading to revascularization. Of this group, 47 % (7/15) underwent percutaneous intervention, and 53 % (8/15) underwent coronary artery bypass grafting. All of these 15 patients had either MVD (14/15) or LM coronary artery disease (1/15), and represented 0.6 % (15/2,659) of all referred patients (95 % CI 0.3 - 0.9 %). The majority, 90 % (8/9), had severe CAD with typical chest pain. CONCLUSION: A very high CAC score (>1,000) with normal MPI in a small subset of symptomatically stable patients was associated with a moderate incidence of severe CAD (95 % CI 37 - 77 %). Larger studies and/or a meta-analysis of small studies are needed to more precisely estimate the incidence of CAD in this population. This study also supports the concept that a normal MPI result in patients with severe CAD may be due to balanced MVD.

Cryoablation versus RF ablation for AVNRT: A meta-analysis and systematic review.

INTRODUCTION: Atrioventricular nodal reentrant tachycardia (AVNRT) is the most common supraventricular tachycardia referred for ablation. High success rates have been accompanied with a small risk of atrioventricular (AV) block. Cryoablation has been used as an alternative to radiofrequency (RF) ablation, but studies have been underpowered in comparing the 2 techniques. METHODS AND RESULTS: An electronic search and hand-search of reference lists for published and unpublished data was carried out. Comparative studies (cohort and randomized controlled trials) of RF versus cryoablation for AVNRT were identified independently by 2 reviewers. Searches were limited to English language human studies. The primary metameter was long-term AVNRT recurrence (>2 months postprocedure and ECG/electrophysiology study [EPS]-documented) and secondary metameters included acute procedural failure and AV block requiring pacing. A total of 5,617 patients in 14 trials were included in this systematic review. Acute procedural failure with cryoablation was slightly higher than with RF ablation, but the difference was not statistically significant (risk ratio [RR] 1.44 [95% confidence interval; CI 0.91-2.28], P = 0.12). Long-term recurrence was higher with cryoablation (RR 3.66 [95% CI 1.84-7.28], P = 0.0002) even after adjusting for larger (6 mm) cryocatheter tips, "insurance lesions" and longer (>6 months) follow-up duration. RF ablation for AVNRT was associated with permanent AV block in 0.75% of patients, but was not reported in any patients treated with cryoablation (n = 1066, P = 0.01). CONCLUSIONS: Cryoablation is a safe and effective treatment for AVNRT. Although late-recurrence is more common with cryoablation than with RF ablation, avoidance of permanent AVN block makes it an attractive option in patients where the avoidance of AV block assumes higher priority (such as children and young adults).

Antiplatelet and anticoagulation for patients with prosthetic heart valves.

BACKGROUND: Patients with prosthetic heart valves are at increased risk for valve thrombosis and arterial thromboembolism. Oral anticoagulation alone, or the addition of antiplatelet drugs, has been used to minimise this risk. An important issue is the effectiveness and safety of the latter strategy. OBJECTIVES: This is an update of our previous review; the goal was to create a valid synthesis of all available, methodologically sound data to further assess the safety and efficacy of combined oral anticoagulant and antiplatelet therapy versus oral anticoagulant monotherapy in patients with prosthetic heart valves. SEARCH METHODS: We updated the previous searches from 2003 and 2010 on 16 January 2013 and searched the Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library (2012, Issue 12), MEDLINE (OVID, 1946 to January Week 1 2013), and EMBASE (OVID, 1980 to 2013 Week 02). We have also looked at reference lists of individual reports, review articles, meta-analyses, and consensus statements. We included reports published in any language or in abstract form. SELECTION CRITERIA: All reports of randomised controlled trials comparing standard-dose oral anticoagulation to standard-dose oral anticoagulation and antiplatelet therapy in patients with one or more prosthetic heart valves. DATA COLLECTION AND ANALYSIS: Two review authors independently performed the search strategy, assessed trials for inclusion and study quality, and extracted data. We collected adverse effects information from the trials. MAIN RESULTS: One new study has been identified and included in this update. In total, 13 studies involving 4122 participants were included in this review update. Years of publication ranged from 1971 to 2011. Compared with anticoagulation alone, the addition of an antiplatelet agent reduced the risk of thromboembolic events (odds ratio (OR) 0.43, 95% confidence interval (CI) 0.32 to 0.59; P < 0.00001) and total mortality (OR 0.57, 95% CI 0.42 to 0.78; P = 0.0004). Aspirin and dipyridamole reduced these events similarly. The risk of major bleeding was increased when antiplatelet agents were added to oral anticoagulants (OR 1.58, 95% CI 1.14 to 2.18; P = 0.006).For major bleeding, there was no evidence of heterogeneity between aspirin and dipyridamole and in the comparison of trials performed before and after 1990, around the time when anticoagulation standardisation with the international normalised ratio was being implemented. A lower daily dose of aspirin (< 100 mg) may be associated with a lower major bleeding risk than higher doses. AUTHORS' CONCLUSIONS: Adding antiplatelet therapy, either dipyridamole or low-dose aspirin, to oral anticoagulation decreases the risk of systemic embolism or death among patients with prosthetic heart valves. The risk of major bleeding is increased with antiplatelet therapy. These results apply to patients with mechanical prosthetic valves or those with biological valves and indicators of high risk such as atrial fibrillation or prior thromboembolic events. The effectiveness and safety of low-dose aspirin (100 mg daily) appears to be similar to higher-dose aspirin and dipyridamole. In general, the quality of the included trials tended to be low, possibly reflecting the era when the majority of the trials were conducted (1970s and 1980s when trial methodology was less advanced).

Myocardial fibrosis and quality of life in patients with non-ischemic cardiomyopathy: a cardiovascular magnetic resonance imaging study.

Myocardial fibrosis (MF) is a common pathophysiologic endpoint in non-ischemic cardiomyopathy and may be identified by late gadolinium enhancement (LGE) MRI. While associated with future cardiovascular events in hypertrophic cardiomyopathy (HCM) and dilated cardiomyopathy (DCM) the influence of MF on interim quality of life (QOL) has not been explored. In this study we investigate for associations between MF and validated indices of QOL in patients with HCM and DCM. Ninety-eight patients with known cardiomyopathy (n = 56-HCM/n = 42-DCM) underwent LGE-MRI in addition to standardized testing for QOL using the disease-specific Minnesota Living With Heart Failure (MLWHF) and the generic SF-12 questionnaires. LGE-MRI images were blindly analyzed for the presence and volume of MF using validated techniques. All analyses were stratified according to cardiomyopathy sub-type. The mean age of the population was 56.8 ± 12.9 years. MF was identified in 82 % of patients with HCM and 74 % of patients with DCM with respective mean MF burdens of 20.0 and 13.7 % of the left ventricular mass (p = 0.008). QOL scores for those with HCM or DCM, as assessed by both MLWHF and SF-12, were not significantly different between those with versus those without MF, and showed no association with MF burden by quantitative signal analysis. In this study we identified no association between QOL and MF burden by LGE-MRI in patients with HCM or DCM. Therefore, the severity of underlying myocardial tissue disease, a recognized substrate for ventricular arrhythmia, cannot and should not be inferred from the patient's symptom status or QOL.

Risk of arrhythmia and sudden death in patients with asymptomatic preexcitation: a meta-analysis.

BACKGROUND: The incidence of sudden cardiac death (SCD) and the management of this risk in patients with asymptomatic preexcitation remain controversial. The purpose of this meta-analysis was to define the incidence of SCD and supraventricular tachycardia in patients with asymptomatic Wolff-Parkinson-White ECG pattern. METHODS AND RESULTS: We performed a systematic search of prospective, retrospective, randomized, or cohort English-language studies in EMBASE and Medline through February 2011. Studies reporting asymptomatic patients with preexcitation who did not undergo ablation were included. Twenty studies involving 1869 patients met our inclusion criteria. Participants were primarily male with a mean age ranging from 7 to 43 years. Ten SCDs were reported involving 11 722 person-years of follow-up. Seven studies originated from Italy and reported 9 SCDs. The risk of SCD is estimated at 1.25 per 1000 person-years (95% confidence interval [CI], 0.57-2.19). A total of 156 supraventricular tachycardias were reported involving 9884 person-years from 18 studies. The risk of supraventricular tachycardia was 16 (95% CI, 10-24) events per 1000 person-years of follow-up. Children had numerically higher SCD (1.93 [95% CI, 0.57-4.1] versus 0.86 [95% CI, 0.28-1.75]; P=0.07) and supraventricular tachycardia (20 [95% CI, 12-31] versus 14 [95% CI, 6-25]; P=0.38) event rates compared with adults. CONCLUSION: The low incidence of SCD and low risk of supraventricular tachycardia argue against routine invasive management in most asymptomatic patients with the Wolff-Parkinson-White ECG pattern.

Does adenosine response predict clinical recurrence of atrial fibrillation after pulmonary vein isolation?

BACKGROUND: Approximately 30% of patients undergoing pulmonary vein isolation (PVI) for atrial fibrillation (AF) have clinical recurrence of AF, and a great majority of these patients have recovery of vein conduction. Adenosine can be associated with acute recovery of conduction to the pulmonary veins immediately after isolation. However, it is not known whether this is prognostic for permanent recovery of conduction or recurrence of AF. METHODS: Patients with paroxysmal AF underwent PVI, with administration of adenosine after electrical isolation. Those with transient conduction recovery (TCR+) underwent no further ablation and were compared to those without (TCR-) for clinical AF recurrence and conduction recovery at second procedure. RESULTS: Seventy-two consecutive PVI patients were studied (mean age 56.7 ± 9.2, 61 male). Twenty-five (35%) patients had transient recovery of conduction with adenosine. After 1 year, 18 patients (25%) had symptomatic recurrence of AF. In this group of 18 patients, 6 were TCR+ at initial ablation (sensitivity 33%, NPV = 74%). In the remaining group of 54 patients free from AF recurrence, 35 patients (65%) were TCR- at initial ablation (specificity 65%, PPV = 24%). All 18 patients with recurrent AF underwent repeat procedure and had at least 1 pulmonary vein with recurrent conduction. The initial adenosine test correctly predicted 13 out of 36 (36%) veins, with positive predictive value 90% and negative predictive value 15%. CONCLUSIONS: Adenosine testing for TCR does not appear to predict recurrence of clinical AF. TCR- veins remain susceptible to conduction recovery, as determined at the follow-up procedure.

Impact of routine transoesophageal echocardiography on safety, outcomes, and cost of pulmonary vein ablation: inferences drawn from a decision analysis model.

AIMS: The practice of routine vs. selective transoesophageal echocardiography (TEE) surveillance for left atrial appendage or intracavitary thrombus prior to pulmonary vein isolation (PVI) varies widely as evidence to guide this decision in terms of important clinical outcomes is lacking. METHODS AND RESULTS: We constructed a decision analysis model to compare the cost-effectiveness of routine TEE for detection of left atrial thrombus vs. no TEE. The model incorporated health outcomes and costs. Markov methodology was used to follow patients as they transition through varying health states. We examined a hypothetical cohort of patients with symptomatic atrial fibrillation suitable for PVI, and expected outcomes were modelled over a period of 2 years. Simulated patients (SPs) undergoing a strategy of a routine TEE experienced significantly fewer transient ischemic attacks (TIAs) [OR 0.28 (0.22-0.37)], and debilitating strokes [OR 0.23 (0.15-0.33)]. Routine TEE led to an absolute risk reduction for stroke of 1.2% [number needed to treat (NNT) 84 (79-100)] and 1.9% for TIA [NNT 53 (48-59)]. The incremental cost-effectiveness ratio (ICER) for TEE was $226,608 per quality-adjusted life year (QALY). The ICER for TEE among high-risk SPs, with pre-existing clot in the left atrium, was $2232 per QALY. CONCLUSION: Decision analysis and microsimulation suggest that routine use of TEE in an unselected population prior to PVI lowers the incidence of cerebral thrombo-embolic events but with considerable cost per QALY.

An echocardiographic study of the limitations of the Tei index in aortic stenosis.

BACKGROUND: The omnibus Tei index, the sum of isovolumic contraction and relaxation times divided by the ejection time, is a good indicator of global cardiac function. However, these time intervals can be influenced by valvular heart disease and the role of the Tei index among patients with aortic stenosis (AS) and left ventricular systolic dysfunction remains incompletely defined. METHODS: Doppler time intervals were measured retrospectively by two observers, and the Tei index were calculated on 80 patients with various degrees of left ventricular systolic dysfunction and severity of AS. Differences between observers were resolved by consensus. Ejection fraction (EF) was visually estimated, and the aortic valve area (AVA) was calculated using the continuity equation. RESULTS: The mean AVA was 1.1+/-0.5 cm(2) and the mean EF was 0.39+/-0.15. Although correlation (r = 0.61, P < 0.001) and agreement (intraclass correlation coefficient=0.55) for the Tei index were satisfactory, there were significant differences between observers (P < 0.001). Using consensus data, the mean Tei index was 0.32+/-0.20 and significantly lower among patients with severe compared with less severe AS (P=0.01). The index varied inversely with left ventricular function (P=0.003). However, receiver operating characteristic analysis shows that the Tei index lacks discrimination in accurately identifying poor left ventricular function or severe AS or both. CONCLUSION: The Tei index varies inversely with systolic ventricular function (low index with good EF) and positively with severity of AS (low index with smaller valve area). As such, it may have limited utility among individual patients with AS.

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.

Ejection fraction assessment and survival: an analysis of the Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT).

BACKGROUND: Ejection fraction (EF) is an important method of mortality prediction among cardiac patients, and has been used to identify the highest risk patients for enrollment in the defibrillator primary prevention trials. Evidence suggests that measures of EF by different imaging modalities may not be equivalent. In the SCD-HeFT (Sudden Cardiac Death in Heart Failure Trial), the type of imaging modality for EF assessment was not mandated. METHODS: Baseline assessment of EF was performed using either echocardiography, radionuclide angiography (RNA), or contrast angiography. Multivariable analysis using a Cox proportional hazards model was used to examine whether the modality of assessing EF affected the likelihood of survival. RESULTS: Among the 2,521 patients enrolled in SCD-HeFT, EF was measured by RNA in 616 (24%), echocardiography in 1,469 (58%), and contrast angiography in 436 (17%). Mean EF as measured by RNA was 25.1% +/- 6.9%; by echocardiography, 23.8 +/- 6.9%; and by angiography, 21.9 +/- 6.9%. These measures were significantly different (P < .001), and each pairwise comparison differed significantly (P < .001 for each). Multivariable analysis showed no significant difference in survival between patients enrolled based on RNA versus echocardiography (HR 1.06, 95% CI 0.88-1.28), RNA versus angiography (HR 1.25, 95% CI 0.97-1.62), or echocardiography versus angiography (HR 1.18, 95% CI 0.94-1.48). CONCLUSIONS: Among patients enrolled in SCD-HeFT, the distribution of ejection fractions measured by radionuclide angiography differed from those measured by echocardiography or contrast angiograms. Survival did not differ according to modality of EF assessment.

Is defibrillation testing still necessary? A decision analysis and Markov model.

OBJECTIVE: To assess the impact of defibrillation threshold (DFT) testing of implanted cardioverter-defibrillators (ICDs) on survival. BACKGROUND: DFT testing is generally performed during implantation of ICDs to assess sensing and termination of ventricular fibrillation. It is common clinical practice to defibrillate ventricular fibrillation twice at an output at least 10 J below the maximum output of the device, providing a 10 J safety margin. However, there are few data regarding impact of DFT testing on outcomes. METHODS: Decision analysis and Monte Carlo simulation were used to assess expected outcomes of DFT testing. Survival of a hypothetical cohort of patients was assessed according to two strategies-routine DFT testing at time of ICD implant versus no DFT testing. Assumptions in the model were varied over a range of reasonable values to assess outcomes under a variety of scenarios. RESULTS: Five-year survival with DFT and no-DFT strategies were similar at 59.72% and 59.36%, respectively. The results were not sensitive to changing risk estimates for arrhythmia incidence and safety margin. Results of the Monte Carlo simulation were qualitatively similar to the base case scenario and consistent with a small and nonsignificant survival advantage with routine DFT testing. CONCLUSIONS: The impact of DFT testing on 5-year survival in ICD patients, if it exists, is small. Survival appears higher with DFT testing as long as annual risk of lethal arrhythmia or the risk of a narrow safety margin is at least 5%, although the incremental benefit is marginal and 95% confidence intervals cross zero. A prospective randomized study of DFT testing in modern devices is warranted.

Survival rates as a guide to implanted cardioverter-defibrillator replacement strategies for device recalls--adding statistical insight to clinical intuition.

BACKGROUND: Recalls and advisories of implanted cardioverter-defibrillators (ICDs) have become an unfortunate reality of cardiac rhythm management. With a paucity of data available on which to base replacement decisions, our goal is to model the potential risks and benefits of ICD generator replacement. The estimated risks are varied through a wide range to determine the potential range of outcomes. METHODS AND RESULTS: Using initial estimates of risk derived from real data on 2915 advisory devices from 17 implanting centers, a decision analysis and Markov model were used to estimate survival according to device replacement decision. Survival rates at 5 years with and without device replacement were estimated at 60.38% and 60.66%, respectively. This difference was not significantly different on comparative analysis, using variability determined by Monte Carlo simulation. One-way and two-way sensitivity analyses are presented, demonstrating the minimal effect of varying estimates of risk. Only variation in risk of device failure had a differential effect on survival, with a survival benefit at 7 years if annual risk of device failure is at least 1.8%. Little differential effect on survival was demonstrated by variation of estimates of arrhythmia risk, nonarrhythmic mortality, and postprocedure infection rate. CONCLUSIONS: Survival rates with a generator replacement or nonreplacement strategy in response to ICD recalls are similar and decrease nearly in parallel over time. The main factor with differential effect on survival is risk of device failure, although the level of this risk required to confer a survival advantage to a replacement strategy is quite large.