Physical frailty in older patients with acute heart failure: From risk marker to modifiable treatment target

Frailty Status Modifies the Efficacy of ICD Therapy for Primary Prevention Among Patients With HF

BACKGROUND

Implantable cardioverter-defibrillator (ICD) therapy is recommended to reduce mortality risk in patients with heart failure with reduced ejection fraction (HFrEF). Frailty is common among patients with HFrEF and is associated with increased mortality risk. Whether the therapeutic efficacy of ICD is consistent among frail and nonfrail patients with HFrEF remains unclear.

OBJECTIVES

The aim of this study was to evaluate the effect modification of baseline frailty burden on ICD efficacy for primary prevention among participants of the SCD-HeFT (Sudden Cardiac Death in Heart Failure Trial).

METHODS

Participants in SCD-HeFT with HFrEF randomized to ICD vs placebo were included. Baseline frailty was estimated using the Rockwood Frailty Index (FI), and participants were stratified into high (FI > median) vs low (FI ≤ median) frailty burden groups. Multivariable Cox models with multiplicative interaction terms (frailty × treatment arm) were constructed to evaluate whether baseline frailty status modified the treatment effect of ICD for all-cause mortality.

RESULTS

The study included 1,676 participants (mean age: 59 ± 12 years, 23% women) with a median FI of 0.30 (IQR: 0.23-0.37) in the low frailty group and 0.54 (IQR: 0.47-0.60) in the high frailty group. In adjusted Cox models, baseline frailty status significantly modified the treatment effect of ICD therapy (Pinteraction = 0.047). In separate stratified analysis by frailty status, ICD therapy was associated with a lower risk of all-cause mortality among participants with low frailty burden (HR: 0.56; 95% CI: 0.40-0.78) but not among those with high frailty burden (HR: 0.86; 95% CI: 0.68-1.09).

CONCLUSIONS

Baseline frailty modified the efficacy of ICD therapy with a significant mortality benefit observed among participants with HFrEF and a low frailty burden but not among those with a high frailty burden.

Comparison of coronary artery calcium scores among patients referred for cardiac imaging tests

BACKGROUND

While coronary artery calcium (CAC) can now be evaluated by multiple imaging modalities, there is presently scant study regarding how CAC scores may vary among populations of varying clinical risk.

METHODS

We evaluated the distribution of CAC scores among three patient groups: 18,941 referred for CAC scanning, 5101 referred for diagnostic coronary CT angiography (CCTA), and 3307 referred for diagnostic positron emission tomography (PET) myocardial perfusion imaging (MPI). We assessed the relationship between CAC score and myocardial ischemia, obstructive coronary artery disease (CAD), and all-cause mortality across imaging modalities.

RESULTS

Within each age group, the frequency of CAC abnormalities were relatively similar across testing modalities, despite an annualized mortality rate which varied from 0.5%/year among CAC patients to 3.8%/year among PET-MPI patients (p < 0.001). Among CCTA and PET-MPI patients, a zero CAC score was common, occurring in ~70% of patients <50 years, ~40% of patients 50-59 years, and ~ 25% of patients 60-69 years. Among CCTA patients, zero CAC was associated with a normal coronary angiogram with high frequency, ranging from 92.2% among patients <50 years to 87.9% among patients ≥70 years. Among PET-MPI patients, zero CAC was associated with a very low frequency of inducible ischemia across all age groups, ranging from 1.5% among patients <50 years to 0.9% among patients ≥70 years.

CONCLUSIONS

In our study, relatively similar CAC scores were noted among patients varying markedly in mortality risk. Clinically, zero CAC scores predicted both a low likelihood of obstructive CAD and inducible myocardial ischemia in all age groups and were observed with high frequency across diagnostic testing modalities.

Assessment of lifestyle-related risk factors enhances the effectiveness of cardiac stress testing

Cardiac stress tests have been widely utilized since the 1960s for the diagnostic and prognostic assessment of patients with suspected coronary artery disease (CAD). Clinical risk is primarily based on assessing the presence and magnitude of inducible myocardial ischemia. However, the primary factors driving mortality risk have changed over recent decades. Factors such as typical angina and inducible ischemia have decreased, whereas the percentage of patients with diabetes, obesity and hypertension have increased. There has also been a marked temporal increase in the percentage of patients who require pharmacologic testing due to inability to perform treadmill exercise at the time of cardiac stress testing and this need has emerged as the most potent predictor of mortality risk in contemporary stress test populations. However, the long-term clinical risk posed by the inability to perform exercise and concomitant CAD risk factors are rarely reflected in the assessment of patients' prognostic risk in cardiac stress test reports. In this review, we suggest that the clinical utility of present-day cardiac stress testing can be improved by developing a more comprehensive assessment that integrates and reports all factors which modulate patients' long-term clinical risk following stress testing. This should include assessment of patients' CAD risk factors, physical activity habits and mobility risks, identification of the reasons why patients could not exercise at the time of cardiac stress testing. In addition, the assessment of four core non-aerobic functional parameters should be considered among patients who cannot exercise: assessment of gait speed, handgrip strength, lower extremity strength, and standing balance.

Biomarkers of Age-Related Frailty and Frailty Related to Diseases: An Exploratory, Cross-Sectional Analysis from the MAPT Study

BACKGROUND

Frailty may in most cases result from two main causes: the aging process (age-related frailty) and diseases (evolving chronic conditions or acute medical illnesses - disease-related frailty). The biological determinants characterizing these two main causes of frailty may be different.

OBJECTIVES

The aim of this study is to compare the biological and neuroimaging profile of people without frailty, those with age-related frailty, and subjects with disease-related frailty in community-dwelling older adults.

MATERIAL AND METHODS

We performed a secondary, cross-sectional analysis from the Multidomain Alzheimer Preventive Trial (MAPT). We included 1199 subjects without frailty throughout the 5-year follow-up, 82 subjects with incident age-related frailty, and 53 with incident disease-related frailty. Available blood biomarkers involved nutritional (eg, vitamin D, omega-3 fatty acids), inflammatory-related (IL-6, TNFR1, GDF15), neurodegenerative (eg, beta-amyloid, neurofilament light chain) and neuroimaging markers (MRI, Amyloid-PET).

RESULTS

Although not statistically significant, the results of the unadjusted model showed increasing gradients for inflammatory markers (GDF15, TNFR1) and decreasing gradients for nutritional and neuroimaging markers (omega 3 index, hippocampal volume) from age-related frailty participants to individuals with disease-related frailty. Considering the linear models we observed higher GDF15 values in disease-related frailty group compared to age-related frailty individuals [β = 242.8 (49.5, 436.2)]. We did not find any significant difference between subjects without frailty and those with age-related frailty. Subjects with disease-related frailty compared to subjects without frailty had lower values of DHA [β = -2.42 (-4.76, -0.08)], Omega 3 Index [β = -0.50 (-0.95, -0.06)] and hippocampal volume [β = -0.22 (-0.42,-0.02)]. They also had higher values of GDF15 [β = 246.1 (88.9, 403.4)] and TNFR1 [β = 157.5 (7.8, 307.2)].

CONCLUSION

Age-related frailty and disease-related frailty may represent different degrees of frailty severity on a biological level. Further research is needed to identify biomarkers potentially able to distinguish these classifications of frailty.