P2592Combining home monitoring temporal trends and baseline patient risk profile for predicting impending heart failure hospitalizations. Results from the SELENE HF (BIO.Detect HF IV) study

Background/Introduction

The lack of a validated method to efficiently combine information provided by Remote Monitoring (RM) of implantable defibrillators (ICD) and patient clinical profile has limited the use of RM in the prevention of worsening heart failure episodes.

Purpose

Our objective was to develop and validate an index combining RM temporal trends and a baseline risk score for predicting the first HF hospitalization after device implantation.

Methods

We prospectively enrolled 918 patients (81% male, median age 69, interquartile interval [QI], 61/76; Seattle Heart Failure Score [SHFS], 0.17, QI, −0.40/0.75) with indication to ICD (56%), or ICD with cardiac resynchronization therapy (44%). The Home Monitoring (HM) system was activated in all patients after implant to collect several technical and HF-related variables daily. Investigators were blinded to HM reports, and only received automatic alerts for critical technical issues. The primary endpoint was the first adjudicated HF hospitalization. The cohort was a posteriori 1:1 randomized in derivation and validation groups stratified by device type and primary endpoint occurrence. The SHFS was used for baseline risk assessment.

Results

During a median follow-up of 23 months (QI, 14/36), 62 first HF hospitalizations were adjudicated. In the derivation group, the index was constructed by combining the SHFS and temporal trends of 24-hour and rest mean heart rates, ventricular ectopic beat frequency, arrhythmic atrial burden, heart rate variability, physical exercise, and thoracic impedance. Variable selection was based on an automatic stepwise procedure, after applying appropriate transformations in variable-specific time frames to maximize the area under the receiver operating characteristics curve (AUC). The resulting index was associated to an AUC of 0.88 and an Odds Ratio of 2.72 (confidence interval [CI] 1.97–3.75, p<0.001) for index unitary increase. In the index validation test, first HF hospitalizations were predicted with a sensitivity of 73.3% (CI, 54.1%-87.7%), a median alerting time of 55 days (QI, 20/68), false alert rate of 0.75 (CI, 0.70–0.81) patient-year, and 95.1% false-alert-free days.

Conclusion

HM temporal trends of selected variables and the SHFS may be combined to timely and efficiently predict the first HF hospitalization after implant, with less than 1 expected per-patient false alert per year.

Acknowledgement/Funding

BIOTRONIK SE & Co. KG, Berlin, Germany

Implantable cardioverter defibrillator in sport participation

Although athletic participation lowers cardiovascular risk and improves quality of life, it may represent a hazard in high-risk group athletes such as those with cardiac abnormalities receiving an implantable cardioverter defibrillator (ICD). ICD sports participants are exposed to the potential risk of inappropriate shocks due to sinus tachycardia and other supraventricular arrhythmias during exertion as well as device injury. The safety of athletic participation of ICD-patients is not completely defined and ICD efficacy in interrupting malignant arrhythmias during intense exercise is partly unknown. This explains difficulties in current recommendations made by physicians, given the associated potentially ischemic, autonomic and metabolic conditions. The scope of this review is to underline specific considerations including potential risks and recommendations for athletic participation in this patient-group.

Atrial fibrillation in athletes

Many studies have shown a relationship between long-term endurance sport practice and atrial fibrillation. Inflammation, anatomic remodelling, alterations in the autonomic system and neurohormonal activation are all possible explanations for the increased prevalence of this arrhythmia in athletes. Atrial fibrillation may determine disabling symptoms like palpitations and impaired physical performance, compromising eligibility for competitive activities, but exclusion from sport is not necessary for all athletes. Limited data are available on drug therapy and recently ablation resulted to be a particularly attractive option for young athletes with paroxysmal atrial fibrillation. The purpose of this review is to discuss mechanisms, clinical features, management of atrial fibrillation in competitive athletes, including criteria for eligibility and disqualification in sport practice.

Which factors predict the behavior of ventricular extrasystoles in athletes over time?

Spontaneous behavior of ventricular extrasystoles (VE) was analysed. From a database containing 578 athletes with VE, 84 males and 11 females (29.9 ± 18.1 years) having ≥ 100 VE or repetitive VE [ventricular couplets (VC) or ventricular tachycardias (VT)] at first 24-hour Holter electrocardiographic monitoring (24-h-HM) (baseline) and at least 1-year of follow-up (3.1 ± 2.2 years) over the past 10 years were selected. The baseline was compared with the last 24-h-HM to establish DVE (VE reduction of at least 98%/24 h in the absence of VC or VT). SDVE was calculated as standard deviation of the number of VE on serial 24-h-HMs. DVE and SDVE were considered as dependent variables. Independent variables were: age, sex, type of sport, symptoms, baseline VE rate (BVE), baseline VC and VT, VE morphology, VE behavior during the baseline training session, disqualification from competitive sports, echocardiographic abnormalities. DVE occurred in 32 athletes (34%). SDVE varied from 0 to 12,658 VE/24 h (1916 ± 2649.9). Disappearance of VE during the baseline training session (DVET) correlated to DVE (P = 0.0319). BVE directly correlated to SDVE (P = 0.0008). Athletes' VE are highly variable over time, their variability depending on BVE, and they not infrequently tend to disappear. The only useful variable for predicting DVE is DVET.

Incidence of paroxysmal atrial tachycardias in patients treated with cardiac resynchronization therapy and continuously monitored by device diagnostics

AIMS

Little is known about the incidence of paroxysmal atrial tachycardias (PAT) in patients with heart failure (HF). The availability of cardiac resynchronization therapy (CRT) devices with extended diagnostics for AT enables continuous monitoring of PAT episodes. The aim of the study was to assess the incidence over time of PAT in HF patients treated with CRT.

METHODS AND RESULTS

Consecutive patients in NYHA functional class III or IV despite optimal drug therapy, QRS duration > or = 130 ms, left ventricular ejection fraction < or = 35%, and left ventricular end-diastolic dimension > or = 55 mm were eligible for enrolment. Patients with permanent or persistent atrial fibrillation (AF) were not included in the study. The first follow-up examination was performed 2 weeks after implantation, to optimize atrial sensing and CRT. Subsequent follow-up examinations were carried out 15 and 28 weeks after implantation, to collect the telemetric data. A total of 173 patients (67 +/- 11 years, M 116) were enrolled. Complete arrhythmia monitoring data were available from 120 patients over a mean follow-up of 183 +/- 23 days. Atrial tachycardia episodes were detected through telemetry in 25 of 120 patients (21%) during at least one follow-up examination. Atrial tachycardia episodes were recorded in 29 and 17% (P = NS) of patients with and without previous history of AF, respectively.

CONCLUSION

More than 20% of the overall HF patient population treated with CRT suffer PAT episodes. Paroxysmal atrial tachycardia may interfere with response to CRT. Therefore, telemetric data may be relevant to drive the appropriate therapy in each patient.

Post automatic implantable cardioverter defibrillator implant therapies: drugs and ablative techniques

The aim of this article is to report the evidences about the use of drugs and ablation after implantation of a cardioverter defibrillator. Drugs can be utilized to prevent appropriate and inappropriate shocks, can influence positively or negatively defibrillation threshold, can be useful for the treatment of electrical storm. Ablation can be performed for direct cure of coexisting atrial and ventricular tachyarrhythmias or for AV node modulation. In particular, previous data demonstrate that rescue ventricular tachycardia ablation of drug-refractory electrical storm is possible by a substrate-orientated ablation approach even in patients with complex chronic infarction and various ventricular tachycardias. At the end of this article it is described how remote monitoring, a new very promising technical improvement, can be utilized for deciding, almost in real time, the use of both these therapies or for controlling their efficacy.

Is implantable defibrillator indicated in all patients on cardiac resynchronization therapy?

Implantable cardioverter defibrillator (ICD) and cardiac resynchronization therapy (CRT) have been introduced during the recent years to improve survival, decrease hospital readmissions and mortality, and to improve functional status and quality of life for patients with heart failure and left ventricular systolic dysfunction (LVSD). Studies which evaluated the use of CRT or ICD alone or compared CRT with CRT-ICD in patients with heart failure and LVSD are listed in this article. The results obtained are already influencing clinical practice in the US, where it has been estimated that 90% of patients receiving a CRT device now are being implanted with an ICD component. However, it is still today debated whether patients with LVSD and heart failure should be routinely offered a CRT-ICD. In fact, there are some issues that still should be solved before to establish indication for CRT-D in all heart failure patients with an indication for CRT: 1) a non complete agreement among the different societies which wrote recommendations for guidelines (a comparative table is reported); 2) a better identification of implantable patients and an amelioration of utilized devices; 3) economic and ethical ramifications of this therapy. Anyway still now the crucial question is: ''Can resynchronization be done in isolation or must be accompanied by an ICD device?''. To answer to this question we can only express which is, in our opinion, the actual position of many physicians who work in the field of pacing and electrophysiology: ''The lesson to be learned is that we still can not predict surely which patient will die of sudden death. Until a method of identifying the high risk patients can be developed, the safest strategy should be to advise a combined ICD-CRT device for patients with indication for CRT''.

Role of natriuretic peptides in heart failure patients with special reference to those on cardiac resynchronization therapy

In recent years natriuretic peptides (NPs) have emerged as important tools for evaluation of heart failure patients. Since its approval by the Food and Drug Administration (FDA) in November 2000, recent surveys suggest that approximately 83% of hospitals in the US use some type of NP testing. Although NP testing was originally focused on rapid diagnosis of patients presenting to the emergency department with shortness of breath, clinicians regularly look to NPs for diagnosing minimally symptomatic or asymptomatic left ventricular dysfunction, and using NPs levels in clinic to help ascertain when decompensation is present. NP testing is now included in the guidelines for the diagnosis and treatment of chronic heart failure and in the Italian Consensus Document for the clinical use of NPs. Recommendations indicate that assessment of NPs can be considered a reliable rule-out test of heart failure in primary care and in the emergency room even if they stated that the role for treatment monitoring or for prognostic evaluation needs to be determined. In recent years, cardiac resynchronization therapy (CRT) was introduced as a new treatment modality for patients with systolic heart failure and several studies suggest that plasma concentration of NPs ensues as a very useful parameter for evaluating and monitoring patients who undergo CRT. Thus this article aims not only to summarise data concerning NPs measurement in patients with heart failure, but also to indicate how these markers could be utilized in the future to objectively assess effects of CRT (identification of responders). In conclusion, if further studies will confirm above mentioned remarks, it would be possible that NPs evaluation can help to tailor the more suitable therapy for each heart failure patient and, therefore, to reduce the number of failures.

Resynchronization of mitral valve annular segments reduces functional mitral regurgitation in cardiac resynchronization therapy

AIM

Cardiac resynchronization therapy (CRT) reduces the severity of functional mitral regurgitation (FMR) in patients with heart failure and left bundle branch block. Our hypothesis was that the induction of a more synchronous mitral valve anulus contraction can be a mechanism of FMR reduction in CRT patients.

METHODS

An echo tissue Doppler imaging (TDI) examination was performed at baseline and 6 months after biventricular pacing system implant in 30 patients (4 females and 26 males, 74.1+/-6.1 years) with dilatative or ischemic chronic heart failure, NYHA class = or >III, ejection fraction (EF) = or <35% and QRS = or >140 ms. EF, Myocardial Performance Index (MPI), left end-diastolic and systolic volumes (LVEDV, LVESV), mitral regurgitation jet area/left atrial area (JA/LAA), effective regurgitant orifice area (EROA), mitral anulus contraction (MAC) were evaluated. Using TDI, at the 6 left ventricle (LV) basal segments the time to the peak myocardial sustained systolic velocity (Ts) and the standard deviation (SD) of TS were evaluated.

RESULTS

At 6 months follow-up NYHA class, EF, MPI were significantly improved, LV volumes were reduced. FMR degree, evaluated both as JA/LAA and EROA, was significantly reduced. This effect was associated with the 6 basal segments resynchronization and with a more effective annular contraction.

CONCLUSIONS

Our data show that CRT by resynchronizing left ventricular basal segments produces a more effective mitral valve annulus contraction and contributes to FMR improvement. Further studies need to evaluate if this could be taken into account as new therapeutic perspective of functional mitral valve regurgitation.