Hemodynamic Monitoring of PA Pressures in Heart Failure
What is the impact of monitoring changes in pulmonary artery (PA) pressures in patients with heart failure (HF)?
The study investigators examined the PA pressure trends from the first consecutive 2,000 patients implanted with the CardioMEMS Sensor with at least 6 months of follow-up. They evaluated changes in PA pressures using an area under the curve (AUC) methodology to estimate the total sum increase or decrease in pressures (mm Hg-day) during the follow-up period relative to the baseline pressure. They compared the PA pressure trends with that of the historic CHAMPION (CardioMEMS Heart Sensor Allows Monitoring of Pressure to Improve Outcomes in New York Heart Association Class III Heart Failure Patients) clinical trial. The AUC results are reported as mean ± 2SE, and p-values comparing the AUC of general-use cohort with outcomes in the CHAMPION trial were computed by t-test with equal variance.
Demographics of the 2,000 HF patient study cohort include average age 70 ± 12 years old, 60% male, 34% with preserved ejection fraction (EF), and average follow-up period was 333 ± 125 days. The mean EF for the population was 33.5%. The left ventricular EF in all the patients ranged from 5% to 75%. Baseline measures of systolic, diastolic, and mean PA pressures were significantly higher in the general-use cohort (p < 0.05). The investigators found that at implant, the mean PA pressure for the general-use patients was 34.9 ± 10.2 mm Hg, compared with 31.3 ± 10.9 mm Hg for CHAMPION treatment and 32.0 ± 10.5 mm Hg for CHAMPION control groups. The mean PA pressure in the general-use population was reduced from 34.9 ± 10.2 mm Hg to 31.6 ± 10.4 mm Hg after 6 months (p < 0.001). The general-use patients had an AUC of -32.8 mm Hg-days at the 1-month time mark, -156.2 mm Hg-days at the 3-month time mark, and -434.0 mm Hg-days after 6 months of hemodynamic guided care, which was significantly lower than the treatment group in the CHAMPION trial. Patients consistently transmitted pressure information with a median of 1.27 days between transmissions after 6 months. Utilization of the system was observed at a median of 98.6% (interquartile range [IQR], 82.9-100.0%). Median utilization for patients aged <65 years was 96.9% (IQR, 72.7-100.0%) and those aged >65 years was 100% (IQR, 87.5-100.0%), p value < 0.001. Median utilization for males was 98.4% (IQR, 82.9-100.0%) and for females was 100% (IQR, 82.9-100.00%), p value = 0.099.
The study investigators concluded that general-use of implantable hemodynamic technology in a nontrial setting leads to significant lowering of PA pressures.
This is an important study because it demonstrates the efficacy of monitoring PA pressures in the ‘real-world’ setting, particularly in the ‘motivated’ patient. It would be interesting to know down the road whether lowering of PA pressures results in survival benefit.
Keywords: Diastole, Geriatrics, Heart Failure, Hemodynamics, Monitoring, Ambulatory, Pulmonary Artery, Secondary Prevention, Stroke Volume, Systole
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