Niraj Varma

Remote monitoring of cardiovascular implanted electronic devices: a paradigm shift for the 21st century.

Traditional follow-up of cardiac implantable electronic devices involves the intermittent download of largely nonactionable data. Remote monitoring represents a paradigm shift from episodic office-based follow-up to continuous monitoring of device performance and patient and disease state. This lessens device clinical burden and may also lead to cost savings, although data on economic impact are only beginning to emerge. Remote monitoring technology has the potential to improve the outcomes through earlier detection of arrhythmias and compromised device integrity, and possibly predict heart failure hospitalizations through integration of heart failure diagnostics and hemodynamic monitors. Remote monitoring platforms are also huge databases of patients and devices, offering unprecedented opportunities to investigate real-world outcomes. Here, the current status of the field is described and future directions are predicted.

Right Ventricular Pacing Increases Risk of Appropriate Implantable Cardioverter–Defibrillator Shocks Asymmetrically: An Analysis of the ALTITUDE Database

Background: Right ventricular pacing (RVP) increases risk of atrial fibrillation in patients with implantable cardioverter–defibrillators (ICDs), but ventricular proarrhythmia is less clear. We analyzed a large remote monitoring database to assess this question. Methods and Results: Patients with single- or dual-chamber ICDs, engaged in remote monitoring for at least 6 months and with unchanged tachycardia programming, were included. %RVP was derived for each weekly transmission. ICD electrograms preceding the first shock were adjudicated. Among 425u2009625 transmissions received from 8435 patients, 389 appropriate shocks occurred over a mean follow-up of 15.0±8.8 months. In a time-dependent Cox proportional hazards model, transmissions with 80% to 98% RVP were associated with a hazard ratio of 1.56 for an appropriate shock in the subsequent week compared with <1% RVP (95% CI, 1.01–2.41; P=0.04). By contrast, ≥98% RVP trended toward a lower risk of an appropriate shock (hazard ratio, 0.61; 95% CI, 0.33–1.12; P=0.108). Lifetime cumulative %RVP was closely correlated with weekly %RVP (R2=0.907) and was similarly associated with increased risk of appropriate shocks at 80% to 98% RVP (hazard ratio, 1.57; 95% CI, 1.01–2.44; P=0.046) but not at ≥98% RVP (hazard ratio, 0.49; 95% CI, 0.24–1.01; P=0.052). These results were driven by dual-chamber devices, but unaffected by PVC counts or programming. Male sex and age were also associated with appropriate ICD shocks. Conclusions: Increasing frequency of RVP is associated with a progressively increased risk of appropriate ICD shocks until ≥98% RVP. RVP may have ventricular proarrhythmia because of competition of paced and intrinsic rhythm in ICD patients.

Effect of Cardiac Resynchronization Therapy on Left Ventricular Remodeling in Patients with Cardiac Sarcoidosis

Cardiac resynchronization therapy (CRT) has been shown to be beneficial in patients with medically refractory heart failure. Although it has been found to be effective in a wide range of etiologies for nonischemic cardiomyopathy, its role in improving remodeling and survival of patients with cardiac sarcoidosis (CS) remains undefined. We performed a retrospective review of all patients at our institution with CS who underwent implantation of a CRT device from 2007 to 2017. The outcomes of this population were compared with the outcomes of a cohort of patients with nonischemic cardiomyopathy with an etiology other than sarcoidosis. Nineteen patients in our institution with CS underwent CRT implantation during the time period. This group was compared with 311 consecutive patients with other etiologies of nonischemic cardiomyopathy who underwent CRT implantation. CRT improved left ventricular ejection fraction (LVEF) from 28.8% to 35.9% (p <0.05) in CS, whereas it improved LVEF from 25% to 36.6% (p <0.01) in non-CS group (difference in means of 0.13). CRT significantly improved diastolic and systolic LV diameters, mitral regurgitation, and right ventricular systolic function in non-CS patients but failed to improve same parameters in CS patients. In conclusion, CRT significantly improved LVEF in patients with CS. There is no significant evidence that survival outcomes of CRT patients with CS are significantly worse than other etiologies of nonischemic cardiomyopathy.

Roundtable Discussion: Optimal Strategies for Improving CRT Outcomes within the Real-World Practice Setting

Gery Tomassoni, MD, FACC, FHRS (Lexington, KY, USA): In this roundtable discussion portion the Optimal Strategies for Improving CRT Outcomes within the Real-World Practice Setting, we are going to start with several questions. I will start the session by asking Dr. Singh and Dr. Varma how they determine if a patient responds adequately to cardiac resynchronization therapy (CRT).

THE RATIO OF LEFT VENTRICULAR END SYSTOLIC VOLUME INDEX AND QRS DURATION IS A POTENT PREDICTOR OF RESPONSE IN PATIENTS WITH A LBBB UNDERGOING CARDIAC RESYNCHRONIZATION THERAPY

CRT benefits those patients with advanced heart failure with LV conduction delay as measured by QRS duration (QRSd). An increase in QRSd, however, may result from a combination of electrical delay and mass effect from LV dilation. This balance may be variable such that patients with a small LV and a

Periprocedural Management of Cardiac Resynchronization Therapy

Opinion StatementCardiac resynchronization therapy (CRT) is an important therapy in heart failure but 30xa0%‒40xa0% of patients may not respond. Improving this rate is an important goal and requires attention to candidate selection, intraoperative procedure, and postoperative follow-up. Factors to be considered are QRS morphology, duration, and left ventricular lead position with attention to paced effects on QRS. Postprocedure follow-up is critical to correct interfering conditions (eg, anodal capture, loss of 100xa0% biventricular pacing because of premature ventricular complexes (PVCs) or atrial fibrillation (AF). Echocardiographic improvement following CRT, which may take up to 18xa0months, is a potent predictor of long-term outcomes. Correcting the status of nonresponders, when possible, is important. Remote monitoring, in conjunction with CRT optimization clinics, may facilitate multidisciplinary follow-up and enable early intervention to improve outcome.

Letter by Varma Regarding Article, “Predictors of Response to Cardiac Resynchronization Therapy in The Multicenter Automatic Defibrillator Implantation Trial With Cardiac Resynchronization Therapy (MADIT-CRT)”

To the Editor:nnThe article by Goldenberg et al1 identifies potential indicators of response to cardiac resynchronization therapy. The significance of left atrial volume is extremely interesting, highlighting that the interaction between ventricular pacing …