Aaron M. Wolfson

Chronic heart failure management and remote haemodynamic monitoring

Heart failure (HF) has a large societal and economic burden and is expected to increase in magnitude and complexity over the ensuing years. A number of telemonitoring strategies exploring remote monitoring and management of clinical signs and symptoms of congestion in HF have had equivocal results. Early studies of remote haemodynamic monitoring showed promise, but issues with device integrity and implantation-associated adverse events hindered progress. Nonetheless, these early studies established that haemodynamic congestion precedes clinical congestion by several weeks and that remote monitoring of intracardiac pressures may be a viable and practical management strategy. Recently, the safety and efficacy of remote pulmonary artery pressure-guided HF management was established in a prospective, single-blind trial where randomisation to active pressure-guided HF management reduced future HF hospitalisations. Subsequent commercial use studies reinforced the utility of this technology and post hoc analyses suggest that tight haemodynamic management of patients with HF may be an additional pillar of therapy alongside established guideline-directed medical and device therapy. Currently, there is active exploration into utilisation of this technology and management paradigm for the timing of implantation of durable left ventricular assist devices (LVAD) and even optimisation of LVAD therapy. Several ongoing clinical trials will help clarify the extent and utility of this strategy along the spectrum of patient with HF from individuals with chronic, stable HF to those with more advanced disease requiring heart replacement therapy.

Baseline diastolic pressure gradient and pressure reduction in chronic heart failure patients implanted with the CardioMEMS™ HF sensor: Pulmonary hypertension and pressure reduction

Remote haemodynamic monitoring (RHM) decreases hospitalization rates in patients with chronic heart failure (HF). Many patients with chronic HF develop pulmonary hypertension (PH) secondary to left heart disease with some acquiring combined pre‐capillary and post‐capillary PH (Cpc‐PH). The efficacy of RHM in achieving pulmonary pressure reductions in patients with Cpc‐PH vs. isolated post‐capillary PH (Ipc‐PH) is unknown. The purpose of this study is to evaluate whether a higher baseline diastolic pressure gradient (DPGbaseline) measured at the time of CardioMEMS™ HF sensor implantation is associated with lower reductions in pulmonary artery diastolic pressures (PADP).

Effects of pressure variation and atrial fibrillation on CardioMEMS™ HF measured pulmonary artery diastolic pressure: comparison of device-averaged and visually inspected waveforms

OBJECTIVE Heart failure (HF) management guided by implantable hemodynamic monitoring reduces hospitalization rates. Hemodynamic data from the CardioMEMS™ HF system includes device-averaged pulmonary artery pressures (PAP) and heart rate. Agreement of device-averaged values compared to the standard method of visual inspection of pressure waveforms at end-expiration is unknown. We evaluated the agreement between device-averaged and visually inspected end-expiratory PAP. APPROACH Twenty-one patients implanted with the CardioMEMS™ HF system were evaluated. Eight-hundred twenty-three PAP waveforms from the Merlin remote monitoring website were visually inspected and pulmonary artery systolic pressure (PASP) and pulmonary artery diastolic pressure (PADP) at end-expiration were recorded. Waveforms were evaluated for pressure variation (PV), defined as the difference between highest and lowest PASP measurement of  ⩾20 mmHg. Bland-Altman analysis quantified differences between device-averaged and visually inspected waveforms. MAIN RESULTS All patients were NYHA functional class III, mean age was 67  ±  15 years and 15 (71%) had AF. Bland-Altman analysis of all waveforms revealed a mean-difference in PADP of  -1.4 mmHg, indicating that visually inspected values were higher than device-averaged values. For PV  ⩾20 mmHg, this value increased to  -2.8 mmHg. The mean-difference comparing waveforms from patients with or without AF was  -1.3 and  -1.6 mmHg, respectively. The 95% limits of agreement were  >50% wider for waveforms from patients with versus without AF (10.3 versus 6.7 mmHg). SIGNIFICANCE There is good agreement between device-averaged and visually inspected waveforms when pressure variation is  <20 mmHg and for patients without atrial fibrillation.

Pulmonary Arterial Pressure Sensing in a Patient with Left Ventricular Assist Device during Ventricular Arrhythmia

Introduction With the ever-increasing heart failure population, the use of left ventricular assist devices (LVAD) is becoming increasingly more accepted as a treatment for heart failure as destination therapy. In 2013, this became an American Heart Association recommendation as destination therapy. Despite improved mechanical function, the problem of fluid management often persists for these patients. Patients can have problems with volume overload, but in addition they are sensitive to volume and filling pressure reduction. Readmissions among patients with an LVAD remain high, with heart failure as a common indication. In addition, these patients are still prone to ventricular arrhythmias (VA). Patients with LVAD have a high incidence of VA and have been shown to have an improved mortality when treated with an implantable cardioverter-defibrillator (ICD). Fluid management in patients with symptomatic congestive heart failure is improved when guided by pulmonary artery (PA) pressure sensor measurements. There is scant data of this use in the LVAD population, but limited data suggest some utility. Patients with an LVAD often have very depressed left ventricular function and blunted pulse pressure, as the left-sided cardiac output is driven by the LVAD. However, patients may still have intact right ventricular (RV) function that generates a significant pulse pressure in the pulmonary artery. Thus, ambulatory PA pressure measurements may serve as an ambulatory marker of RV function. We hypothesize that PA pressure measurements could be used as a surrogate for RV function and thus hemodynamic stability during VA. If so, could these data be utilized to enhance detection in patients with LVAD support and an ICD?