Introduction and methods

Pulmonary Artery Pressure-Guided Therapy for Ambulatory Heart Failure Patients in Clinical Practice; 1-Year Outcomes from the CardioMEMS Post-Approval Study

Presented at ACC.19 by David Shavelle (Los Angeles, California)

The burden of hospitalization for heart failure (HHF) remains high despite increasingly effective medical therapy. Congestion or increased cardiac filling pressures are the main causes of HHF. Weeks prior to the signs and symptoms that prompt HHF, increases in pulmonary artery (PA) pressures are observed.

The randomized CHAMPION study showed 37% reduction in HHF rates and all-cause hospitalization (ACH) with therapy guided by PA pressures. Based on these data, ambulatory hemodynamic monitoring with an implantable PA sensor (CardioMEMS) is approved for patients with NYHA Class III HF and HHF within the prior 12 months. However, the benefits in clinical practice, especially in the elderly, women and in those with mid-range or preserved ejection fraction (EF) remain unclear. These FDA-mandated post-approval analyses of the CardioMEMS PAS (Post-Approval Study) trial therefore assessed efficacy and safety of PA pressure -guided therapy in clinical practice. CardioMEMS PAS is a prospective, open-label observational study including 1.200 HF patients implanted with the CardioMEMS PA sensor (enrollment between Sept 2014 and March 2018) at 104 centers in the US. Eligible patients (n=859) had NYHA class III HF, ≥1 HHF within the previous 12 months, treatment with beta blockers for 3 months and an ACE inhibitor/ARB for 1 month in those with HFrEF (except in intolerant patients), chest circumference of <65 inches in those with BMI >35, and a PA branch diameter ≥7 mm. Patients served as their own control. The primary efficacy outcome was reduction in rate of HHF at 1-year post-implant compared with the year prior to enrollment. Primary safety endpoints were freedom from device and system related complications >80% at 1 year and freedom from sensor failure >90% at 1 year.

Main results

• Of 1.200 participants, 38% were women, 17% non-white and 71% >65 years.

Efficacy and safety outcomes

• At 1-year post-implant, HHF was reduced with 58% (0.52 vs.1.24 events/patient-year [PY])HR: 0.42, 95%CI: 0.38-0.47, P<0.0001), compared to 1-year pre-implant.
• HHF/death was decreased with 44% (0.69 vs. 1.24 events/PY, HR: 0.56, 95%CI: 0.51-0.62, P<0.0001) at 1-year post-implant, compared to 1-year pre-implant.
• ACH was decreased with 28% (HR : 0.72, 95%CI: 0.67-0.77, P<0.0001) at 1-year post-implant, compared to 1-year pre-implant.
• At 1 year, freedom from device/system related complications was seen in 99.7% and freedom from sensor failure in 99.9%, which is above the objective performance criteria of 80% and 90%, respectively.

Efficacy outcomes in subgroups

• HHF was reduced with 54% (HR: 0.46, 95%CI: 0.40-0.52, P<0.001) in patients with EF <40% (n=637), 63% (HR: 0.37, 95%CI: 0.29-0.48, P<0.001) in participants with EF 41-50% (n=198) and 61% (HR: 0.39, 95%CI: 0.32-0.49, P<0.001) in those with EF >50% (n=363) at 1-year post-implant, compared to 1-year pre-implant.
• Post-enrollment, HHF was consistently and significantly reduced in all subgroups based on gender, cardiomyopathy (ischemic/non-ischemic), device status (ICD/CRT-D or no ICD/CRT-D) or race, compared to pre-enrollment.

Conclusion

Post-approval analyses of the CardioMEMS PAS trial showed that pulmonary artery pressure-guided therapy for HF is effective in reducing HHF, regardless of gender, EF or race, and safe with few device/system related complications and a low rate of pressure sensor failure in patients with NYHA class III HF.

Discussion

Discussant Gurusher Panjrath noted that the benefit was seen across the EF spectrum, which is important. Moreover, the safety signal was very good.

He was impressed by the high compliance rate, which raises the question how this factors in our infrastructure. During the discussion, dr. Shavelle noted that eligible patients are patients who like interaction with their doctors. Because in patients on optimal medical therapy, the device gives advice on the need for up- or downtitration of medication. If the patient does not like to be called by the physician with instructions to change their medication, CardioMEMS may not be the right method to manage this patient.

• Our coverage of ACC.19 is based on the information provided during the congress –