Highlights of the SARAH Trial
The SARAH trial (Sacubitril-Valsartan for the Prevention of Anthracycline Cardiotoxicity in Patients With Elevated hs-cTnI Concentrations During Chemotherapy) provides pivotal evidence for the role of angiotensin receptor-neprilysin inhibitors (ARNI) in the cardio-oncology setting. Key highlights include:
1. Sacubitril-valsartan significantly reduced the incidence of subclinical cardiotoxicity, defined as a >15% reduction in global longitudinal strain (GLS), with a relative risk reduction of approximately 72% compared to placebo.
2. The treatment group demonstrated a 2.5% improvement in mean GLS over six months, contrasting with a .6% decline in the placebo group, illustrating a clear divergence in myocardial function trajectories.
3. While efficacy was robust, clinicians must monitor for hypotension, which occurred significantly more frequently in the sacubitril-valsartan arm.
4. This study reinforces the utility of high-sensitivity cardiac troponin I (hs-cTnI) as a biomarker to trigger primary preventive interventions in oncology patients receiving potentially cardiotoxic regimens.
Introduction: The Challenge of Anthracycline-Induced Cardiotoxicity
Anthracyclines remain a cornerstone of chemotherapy for various malignancies, including breast cancer, sarcomas, and lymphomas. However, their clinical utility is frequently limited by dose-dependent cardiotoxicity, which can lead to irreversible heart failure. Traditional monitoring strategies often relied on detecting a drop in left ventricular ejection fraction (LVEF). Unfortunately, by the time LVEF declines, significant and often permanent myocardial damage has already occurred.
In recent years, the focus of cardio-oncology has shifted toward early detection and prevention. Global longitudinal strain (GLS), measured via speckle-tracking echocardiography, has emerged as a more sensitive marker for detecting subclinical myocardial injury before LVEF changes manifest. Simultaneously, the use of cardiac troponins has become a standard approach to identify patients at high risk for subsequent cardiac dysfunction during chemotherapy.
While ACE inhibitors and beta-blockers have shown some benefit in preventing cardiotoxicity, the search for more effective pharmacological interventions continues. Sacubitril-valsartan, which combines neprilysin inhibition with angiotensin receptor blockade, has revolutionized the treatment of chronic heart failure. The SARAH trial was designed to investigate whether these benefits extend to the prevention of anthracycline-induced injury.
Study Design: The SARAH Trial Framework
The SARAH trial was a randomized, double-blind, placebo-controlled trial conducted to evaluate the efficacy of sacubitril-valsartan in a high-risk oncology population. The study enrolled 114 patients undergoing anthracycline-based chemotherapy who exhibited an elevation in cardiac troponin I (hs-cTnI) concentrations, indicating early myocardial stress or injury.
Participants were randomized in a 1:1 ratio to receive either sacubitril-valsartan or a matching placebo for six months. The target dose for the intervention group was 97/103 mg twice daily, following a standard titration protocol. The primary endpoint was the occurrence of a significant reduction in myocardial function, defined as a >15% decrease in GLS from baseline to the six-month follow-up.
Secondary endpoints were comprehensive, including changes in serum biomarkers (NT-proBNP and hs-cTnI), additional echocardiographic parameters, cardiac magnetic resonance imaging (CMR) findings, and a rigorous assessment of adverse events. The trial followed the intention-to-treat principle, ensuring that all randomized patients were included in the primary analysis.
Primary Efficacy Outcomes: Preserving Myocardial Function
The results of the SARAH trial revealed a statistically significant and clinically meaningful benefit for patients treated with sacubitril-valsartan. The primary endpoint—a reduction in GLS of more than 15%—occurred in only 4 patients (7%) in the sacubitril-valsartan group, compared to 14 patients (25%) in the placebo group. This translated to an odds ratio of 0.23 (95% CI, 0.07-0.75; P=0.015), suggesting that the ARNI significantly protected against subclinical myocardial deformation.
Perhaps more striking was the mean change in GLS over the six-month study period. Patients receiving sacubitril-valsartan experienced a 2.5% improvement in their strain values, suggesting not just protection but potential recovery of myocardial mechanics. In contrast, the placebo group saw a mean decline of 7.6% (P<0.001 between groups). Given that GLS is a robust predictor of future heart failure and cardiovascular mortality, these findings suggest that sacubitril-valsartan may fundamentally alter the cardiovascular trajectory of these patients.
Secondary Endpoints: Biomarkers and Imaging
Despite the clear differences in myocardial strain, the study did not observe significant differences between the two groups regarding changes in cardiac troponin I or NT-proBNP levels during the follow-up period. This suggests that while sacubitril-valsartan mitigates the functional consequences of anthracycline exposure, it may not completely prevent the initial biochemical evidence of cardiomyocyte stress or injury as measured by these specific markers.
Cardiac magnetic resonance imaging and other echocardiographic parameters generally trended in favor of the sacubitril-valsartan group, though the study was primarily powered for the GLS endpoint. The consistency across imaging modalities reinforces the hypothesis that neprilysin inhibition provides a degree of myocardial resilience against the oxidative stress and mitochondrial dysfunction typically induced by anthracyclines.
Safety and Tolerability: Navigating Hypotension Risks
As with any potent vasodilator, safety and tolerability are paramount, particularly in oncology patients who may already be experiencing fatigue, dehydration, or other systemic effects of chemotherapy. In the SARAH trial, sacubitril-valsartan was generally well-tolerated, but there was a notable increase in the incidence of hypotension.
Symptomatic hypotension or a systolic blood pressure drop below 100 mm Hg occurred in 8 patients in the sacubitril-valsartan group compared to only 1 patient in the placebo group (P=0.032). This highlights the necessity for clinicians to employ careful dose titration and regular blood pressure monitoring when initiating ARNI therapy in this population. Other adverse events were balanced between the groups, suggesting that the ARNI does not significantly exacerbate the typical side effect profile of chemotherapy.
Expert Commentary: Sacubitril-Valsartan in the Cardio-Oncology Landscape
The SARAH trial represents a significant step forward in the field of preventive cardio-oncology. Historically, trials such as ICOS-ONE and PRADS have explored the use of ACE inhibitors and statins with varying degrees of success. The robust effect size observed with sacubitril-valsartan in SARAH suggests that neprilysin inhibition may offer superior myocardial protection compared to traditional RAAS inhibition alone.
Mechanistically, the benefits of sacubitril-valsartan likely stem from the combined effect of blocking the harmful effects of angiotensin II while augmenting the beneficial effects of natriuretic peptides. Natriuretic peptides possess anti-fibrotic, anti-apoptotic, and anti-hypertrophic properties, which may directly counteract the mechanisms of anthracycline injury. Furthermore, the improvement in GLS observed in the treatment group suggests that sacubitril-valsartan might facilitate early myocardial repair mechanisms.
However, it is important to acknowledge the study’s limitations. As a pilot investigation with 114 patients, the sample size is relatively small, and the majority of participants were women with breast cancer. Whether these findings can be generalized to other malignancies or more diverse patient populations remains to be confirmed in larger phase III trials. Additionally, the six-month follow-up provides insight into early cardiotoxicity, but long-term data are needed to determine if this early functional preservation translates into lower rates of clinical heart failure years after treatment.
Conclusion: Implications for Clinical Practice
The SARAH trial provides a compelling rationale for the use of sacubitril-valsartan as a primary preventive strategy in patients showing early signs of anthracycline-induced cardiac injury. By using troponin elevation as a trigger for intervention, clinicians can identify a high-risk subgroup that stands to benefit most from intensive cardioprotective therapy.
For clinicians, the takeaway is twofold: first, the importance of serial biomarker and strain monitoring during anthracycline therapy cannot be overstated. Second, sacubitril-valsartan should be considered a viable and effective option for those demonstrating subclinical injury, provided that blood pressure is monitored closely. As the survival rates for cancer continue to improve, the focus must remain on ensuring that the treatments that save lives today do not lead to cardiovascular morbidity tomorrow.
Funding and Registration
The SARAH trial was supported by institutional research funds. It is registered at https://ensaiosclinicos.gov.br (RBR-5q4gm5b) and carries the UTN code U1111-1274-1961.
References
1. Bonatto MG, Avila MS, Ayub Ferreira SM, et al. Sacubitril-Valsartan for the Prevention of Anthracycline Cardiotoxicity in Patients With Elevated Cardiac Troponin I Concentration During Chemotherapy: A Double-Blind Randomized Placebo-Controlled Clinical Trial: The SARAH Trial. Circulation. 2025;152(25):1742-1755.
2. Lyon AR, López-Fernández T, Couch LS, et al. 2022 ESC Guidelines on cardio-oncology developed in collaboration with the European Hematology Association (EHA), the European Society for Therapeutic Radiology and Oncology (ESTRO) and the International Cardio-Oncology Society (IC-OS). European Heart Journal. 2022;43(41):4229-4361.
3. Januzzi JL Jr, Prescott MF, Butler J, et al. Association of Change in N-Terminal Pro-B-Type Natriuretic Peptide Following Initiation of Sacubitril-Valsartan Treatment With Cardiac Structure and Function in Patients With Heart Failure With Reduced Ejection Fraction. JAMA. 2019;322(11):1085-1095.
