key: cord-0990918-2p85nsof
authors: Egolum, Ugochukwu O.; Parikh, Kishan; Lekavich, Carolyn; Wosik, Jedrek; Frazier-Mills, Camille; Fudim, Marat
title: Applications of the Multi-Sensor HeartLogic Heart Failure Monitoring Algorithm during the COVID-19 global pandemic
date: 2020-10-12
journal: JACC Case Rep
DOI: 10.1016/j.jaccas.2020.09.035
sha: d5790cd40c7f93393356ab3998b88ebadc934729
doc_id: 990918
cord_uid: 2p85nsof

In the COVID-19 era, the heart failure community has witnessed an unprecedented reduction in heart failure related patient visits and hospitalizations. Social distancing measures present a dilemma for heart failure patients who require frequent surveillance of volume status and vital signs in order to minimize heart failure related symptoms and hospitalizations. With the rise of telemedicine comes an increased focus on remote monitoring technologies. This report describes use of a multisensor device algorithm in implantable cardioverter defibrillator devices by Boston Scientific, called HeartLogic. We present two cases of patients with advanced heart failure who were actively surveilled by the HeartLogic device algorithm to guide care.

The COVID-19 pandemic has had a significant impact on the way we care for patients, particularly, heart failure (HF) patients who are at higher risk for morbidity and mortality (1) .

The adoption of telehealth has been instrumental though there are inherent limitations (2) . A series of remote monitoring technologies are available which can enhance the surveillance of HF signs and assist clinicians with therapeutic interventions (3) . Remote monitoring for HF patients is available in several forms-1) structured telephone support service with frequent review of HF symptoms, weight, medication compliance etc. and medical plan adjusted based on the patients report, 2) Invasive devices implanted to solely monitor surrogates of left ventricular filling pressures eg. CardioMEMS sensor implanted in the pulmonary artery, results of which are transmitted electronically and medical therapy is adjusted based on the trend in the recordings, 3)

Monitoring via parameters derived from cardiovascular implantable electronic devices (implantable cardioverter defibrillator devices [ICD] and cardiac resynchronization therapydefibrillators [CRT-D]) for eg. Medtronic OptiVol monitoring system that evaluates lung impedance as a surrogate of lung water and volume status (3) . Another device that falls into the latter category is the Boston Scientific HeartLogic HF algorithm (4). The algorithm encompasses multiple sensors which are embedded within certain Boston Scientific ICD and CRT-D. The algorithm generates a daily HF index score which is a proprietary numeric composite of the following physiologic parameters taken together-1) heart sounds (S1 and S3), 2) thoracic impedance, 3) respiration rate [and its ratio to tidal volume], 4) heart rate and 5) patient activity ( Table 1 ) (4) . The device computes every day the deviation of individual sensors from their baseline and calculates a composite index. An alert is triggered when the modular threshold is exceeded (usually set at 16, but can be adjusted by the clinician) signaling a high risk for a HF J o u r n a l P r e -p r o o f event (hospitalization or outpatient intravenous [IV] diuretics). When the patient enters alert status (>16) the index threshold is automatically dropped to a recovery value (nominal value 6).

The sensitivity for detection was reported at 70% while the median time from the alert onset to the HF event occurrence was 34 days indicating the potential for a very early warning, signaling worsening HF (4). Patients can be contacted and adjustments in the care plan maybe instituted thus potentially avoiding hospitalization or need for outpatient IV diuretics particularly during the COVID-19 pandemic.

Past Medical History: A 78 year old man with a history of chronic systolic and diastolic HF (LVEF 40-45%), atrial fibrillation status post ablation x 2, ventricular tachycardia, status post CRT-D, severe tricuspid regurgitation and chronic kidney disease. During a prior work-up for infiltrative cardiomyopathy, he was found to have wild type TTR cardiac amyloidosis and was subsequently initiated on tafamidis.

History of presentation: He was last seen in cardiology clinic in March 2020. He underwent an atrioventricular junction ablation in mid-May for non-optimized biventricular pacing in setting of refractory atrial arrhythmias. Within 1 week following ablation the patient went into HeartLogic status. The HeartLogic report indicated an increase in S3, nighttime heart rate, and respiratory rate without a change in thoracic impedance (Figure 1 ).

Management: The patient was called by the HF clinic and reported weight gain and swelling. Oral diuretics were increased. He was then seen in clinic at the end of May and reported a weight gain of 7 lbs since discharge with recurrent signs of right-sided congestion (lower extremity edema and ascites) on exam as well as exertional dyspnea since the cardiac J o u r n a l P r e -p r o o f ablation procedure despite diuretic increase. NT-proBNP was ~1700 pg/dL (up from 890 last month). Oral diuretics were further escalated, however the patient required admission 2 weeks later for IV diuresis. Inpatient IV diuresis corresponds to a gradual improvement in the HeartLogic score (Figure 1) .

Past showed no arrhythmia. The HF index score was 0 and all prior scores were below the alert threshold signifying a low likelihood of a HF event (Figure 2) . There was no change in the J o u r n a l P r e -p r o o f respiratory rate parameter and his thoracic impedance was trending upwards relative to baseline, suggesting no pulmonary edema.

Management: Sacubitril/valsartan, spironolactone, metoprolol succinate and furosemide (as needed) were continued without changes. The patient was reassured. On telehealth follow up, 1 week later, he was asymptomatic and had safely avoided any direct healthcare contacts. His HF index continues to remain below threshold.

The European Society of Heart Failure Guidelines support the use of remote monitoring devices in improving clinical outcomes (5) . Remote monitoring can take many forms as described in the introduction section. Here we reviewed two cases in which the HeartLogic algorithm provided critical data that expedited care delivery, allowed for appropriate triage of patients, with reduction in unnecessary clinic visits. In the first case HeartLogic was used to surveil a challenging patient with amyloid cardiomyopathy prone to fluid retention. Although the patient experienced clinical signs and symptoms of HF at the time of the initial alert the patient did not seek medical care. Delay in seeking care was in large part due to an anxiety of contracting SARS-CoV-2. The second patient highlighted the other end of the utility of remote monitoring, that is, safely managed at home with good clinical outcome without requiring admission or an outpatient visit.

Here we provide a review of our approach to a HeartLogic index alert (Figure 3) . In brief, this includes intensifying the diuretic regimen and optimizing guideline directed medical therapy after obtaining a detailed history from the patient. Any detected device related issues (eg.

<92% CRT pacing or arrhythmia) is evaluated and managed by the care team electrophysiologist. In addition to treatment, the HF algorithm allows for evaluation of other J o u r n a l P r e -p r o o f differential diagnosis as noted in the case review. The HeartLogic data can be used for more than diuretic medication optimization, such as adjusting beta-blockers in response to the recorded heart rate. The activity parameter can facilitate monitoring of how sedentary the patient is, prompting encouragement for more activity. Essentially all the monitored parameters can be utilized in a manner to promote improved HF care and may lead to a reduction in admissions for HF and reduce the need for unnecessary cardiology visits and/or evaluations. Additionally, we demonstrated that the HeartLogic can be applied to LVAD patients. Initially there were concerns that the S3 and S1 sounds may not be appreciated, however, the algorithm senses the "sounds" as distinct vibrations and in our experience the presence of an LVAD has not affected the functionality. This presents yet another group of patients that may benefit from HL monitoring given the inherent limitations of the physical exam in these patients i.e. auscultation of the lung and heart sounds is obscured by the LVAD mechanical hum.

The COVID-19 pandemic has changed how and where we care for patients. Remote HF 

To recognize the change in methods used to deliver medical care and that avoiding medical care during the COVID-19 pandemic is common among patients

To appreciate the role of heart failure remote monitoring devices, such as the HeartLogic, in providing care for heart failure patients during the COVID-19 pandemic

Cardiovascular Implications of Fatal Outcomes of Patients With Coronavirus Disease 2019 (COVID-19)

Telehealth transformation: COVID-19 and the rise of virtual care

Telemonitoring in Heart Failure Management

A Multisensor Algorithm Predicts Heart Failure Events in Patients With Implanted Devices: Results From the MultiSENSE Study

Clinical practice update on heart failure 2019: pharmacotherapy, procedures, devices and patient management. An expert consensus meeting report of the Heart Failure Association of the European Society of Cardiology