How to Estimate the Optimal Heart Rate in Patients with Heart Failure with Preserved Ejection Fraction

Clinical Implications of Ivabradine in the Contemporary Era

Ivabradine is a recently introduced inhibitor of the If ion channel, which exhibits the capacity to reduce heart rate while preserving hemodynamic stability. At present, ivabradine finds its clinical indication in patients suffering from heart failure with reduced ejection fraction and maintaining a relative sinus rhythm refractory to beta-blockers. To optimize heart rate control, it is recommended to pursue an aggressive up-titration of ivabradine. This approach may ameliorate tachycardia-induced hypotension by incrementally enhancing cardiac output and allow further up-titration of agents aimed at ameliorating heart failure, such as beta-blockers. Both the modulation of heart rate itself and the up-titration of agents targeting heart failure lead to cardiac reverse remodeling, consequently culminating in a subsequent reduction in mortality and morbidity. A novel overlap theory that our team proposed recently has emerged in recent times. Under trans-mitral Doppler echocardiography, the E-wave and A-wave closely juxtapose one another without any overlapping at the optimal heart rate. Employing echocardiography-guided ivabradine for heart-rate modulation to minimize the overlap between the E-wave and A-wave appears to confer substantial benefits to patients with heart failure. This approach facilitates superior cardiac reverse remodeling and yields more favorable clinical outcomes when compared to those patients who do not receive echocardiography-guided care. The next pertinent issue revolves around the potential expansion of ivabradine's clinical indications to encompass a broader spectrum of diseases. It is imperative to acknowledge that ivabradine may not yield clinically significant benefits in patients afflicted by heart failure with preserved ejection fraction, acute heart failure, sepsis, or stable angina. An important fact yet to be explored is the clinical applicability of ivabradine in patients with atrial fibrillation, a concern that beckons future investigation. In this review, the concept of overlap theory it introduced, along with its application to expand the indication of ivabradine and the overlap theory-guided optimal ivabradine therapy.

Negative Prognostic Impact of Mineralocorticoid Receptor Antagonist in Elderly Patients Receiving TAVR

Background: Morbidity and mortality following trans-catheter aortic valve replacement (TAVR) remain high. Renin-angiotensin system inhibitors improve clinical outcomes in the cohort studied in this work. However, post-TAVR prognostic impact of mineralocorticoid receptor antagonist (MRA), another neuro-hormonal blocker, remains uncertain. Here, we hypothesized that MRA was associated with improved clinical outcomes in elderly patients with severe aortic stenosis receiving TAVR.

METHODS

Consecutive patients who received TAVR at our institute between 2015 and 2022 were considered for inclusion. Propensity score matching analysis was performed to match pre-procedural baseline characteristics between those with and without MRA. The prognostic impact of MRA use on the composite primary endpoint consisting of all-cause death and heart failure during the 2-year observational period following index discharge was evaluated.

RESULTS

Among 352 patients who received TAVR, 112 patients (median 86 years, 31 men) were included, consisting of baseline-matched 56 patients with MRA and 56 patients without MRA. Following TAVR, patients with MRA had more impaired renal function compared with no MRA group. Following index discharge, serum potassium tended to increase, and renal function tended to decline in patients with MRA. Patients with MRA had a higher cumulative incidence of the primary endpoints during a two-year observational period (30% versus 8%, p = 0.022).

CONCLUSIONS

Routine prescription of MRA might not be recommended in elderly patients with severe aortic stenosis receiving TAVR, given its negative prognostic impact. Optimal patient selection for MRA administration in this cohort needs further study.

Efficacy of Doppler echocardiography-guided ivabradine therapy

BACKGROUND

The purpose of this study was to evaluate the advantage of heart rate (HR) modulation using ivabradine referring Doppler echocardiography over the conventional ivabradine therapy without echocardiography guide in patients with systolic heart failure.

METHODS

From October 2020, our institute updated the protocol of ivabradine therapy, in which HR was optimized to minimize the overlap between the two left ventricular inflow waves using Doppler echocardiography (echo-guided group). The degree of cardiac reverse remodeling at 3-month follow-up was compared between the echo-guided group and the conventional ivabradine therapy group treated before October 2020.

RESULTS

A total of 28 patients (62 years old, 17 men) were included, and 18 patients were from echo-guided group. Left ventricular ejection fraction increased significantly in the echo-guided group (from 41% [28%, 49%] to 55% [37%, 66%], p = 0.007), whereas it remained unchanged in the conventional group (p = 0.333). Systolic blood pressure and the daily dose of carvedilol increased significantly only in the echo-guided group (p = 0.009 and p = 0.001, respectively).

CONCLUSIONS

Among those with systolic heart failure, a Doppler echocardiography guide might be a promising therapeutic tool in modulating HR by ivabradine in facilitating reverse remodeling.

Combination therapy using tafamidis and neurohormonal blockers for cardiac amyloidosis and a reduced ejection fraction: a case report

Cardiac amyloidosis usually presents with diastolic dysfunction, but sometimes systolic dysfunction develops, particularly at its advanced stage. However, the therapeutic strategy for patients with cardiac amyloidosis and systolic dysfunction remains unknown. We report a 77-year-old man who was diagnosed with wild-type cardiac amyloidosis and systolic dysfunction with a left ventricular ejection fraction of 27%. Following 6-month medical therapy of tafamidis 80 mg and neurohormonal blockers (carvedilol 5.0 mg, enalapril 2.5 mg, and spironolactone 25 mg), the left ventricular ejection fraction improved to 55%. Tafamidis-incorporated neurohormonal blocker therapy might be a promising strategy to facilitate cardiac reverse remodeling in patients with cardiac amyloidosis and systolic dysfunction.

Therapeutic Strategy for Heart Failure with Reduced Ejection Fraction and Cardiac Amyloidosis

We sometimes encounter patients with systolic heart failure and cardiac amyloidosis. Neurohormonal blockers are guideline-directed medical therapy for those with systolic heart failure. However, its implication among the above cohort remains controversial. Of 3 patients with systolic heart failure and cardiac amyloidosis who we encountered, cardiac reverse remodeling was achieved in 2 patients who received neurohormonal blockers, whereas cardiac function remained unchanged in a patient not receiving neurohormonal blockers. Neurohormonal blockers might be keys to achieve cardiac reverse remodeling and favorable clinical outcomes even in patients with systolic heart failure and cardiac amyloidosis, although further larger-scale studies are required to validate our hypothesis.

Optimal Heart Rate and Prognosis in Patients with Cardiac Amyloidosis

Background: Optimal heart rate (HR) that associates with higher cardiac output and greater clinical outcomes in patients with cardiac amyloidosis remains unknown. Methods: Consecutive patients with sinus rhythm who were diagnosed with cardiac amyloidosis at our institute between February 2015 and February 2021 were retrospectively included. Ideal HR, at which E-wave and A-wave stand adjacent without any overlaps in the trans-mitral flow echocardiography, was calculated by the formula: 86.8−0.08 × deceleration time (msec). The association between optimal HR and cardiac death or heart failure readmission was investigated. Results: Ten patients (median 74 years old, 8 men) were included. On median, actual HR was 64 bpm and ideal HR was 69 bpm. An incidence rate of the primary endpoint in the sub-optimal HR group tended to be higher than optimal HR group: one of the four patients in optimal HR group had events (25%); two of the two patients in higher HR group had events (100%); two of the four patients in lower HR group had events (50%). Conclusions: The optimal HR was associated with greater clinical outcomes in patients with cardiac amyloidosis. The clinical impact of aggressive HR optimization in this cohort remains the next concern.