Cardiovascular effects of BRAF and MEK inhibitors in patients with melanoma: a prospective study incorporating risk scores, cardiac biomarkers and cardiovascular magnetic resonance imaging
Authors: Glen C , Dobbin S J H , Mangion K , Macdonald E , Butler E , Brooksbank K , Coats C , Roditi G , Tan Y Y , Waterston A , Petrie M C , Lang N N 
Published: October 2024

Abstract

Background
BRAF and MEK inhibitors have revolutionised treatment for patients with BRAF-mutated melanoma. Unfortunately, they are associated with cardiovascular adverse effects including hypertension and cancer-therapy related cardiac dysfunction (CTRCD). The ‘real world’ incidence and risk factors for these adverse effects are poorly described.

Purpose
To characterise the incidence and risk factors for BRAF and MEK inhibitor-associated hypertension and CTRCD in a prospective ‘real world’ setting.

Methods
Prospective, observational, cohort study of patients with melanoma treated with BRAF and MEK inhibitors at a regional cancer hospital network (March 2021 - May 2023). Comprehensive assessment was performed at baseline, 4, 12 and 24 weeks following start of treatment, including home and clinic blood pressure assessment, serial echocardiography, stress-perfusion cardiovascular magnetic resonance imaging (CMR) and humoral biomarkers (Figure 1). CTRCD was defined as mild, moderate or severe in line with International Cardio-Oncology Society (IC-OS) definitions. Hypertension was defined as 7 day average home blood pressure of ≥135/85 mmHg or the initiation or escalation of anti-hypertensive therapy. Baseline cardiotoxicity risk stratification was performed using the ESC Cardio-Oncology guideline-recommended tool.

Results
61 participants were enrolled. 48% developed BRAF/MEK inhibitor associated hypertension. 46% of participants developed CTRCD and, of these, 24 (86%) were classified as mild, 3 (11%) moderate and 1 (3%) severe. Left ventricular ejection fraction (LVEF) during follow up is shown in Figure 2. All participants with moderate and severe CTRCD also had BRAF/MEK inhibitor associated hypertension. After stratification with the baseline risk assessment tool, no patient in the ‘low risk’ group developed moderate or severe CTRCD. Baseline elevated NT-proBNP (&gt;125pg/mL), history of left ventricular systolic dysfunction and atrial fibrillation were associated with the development of CTRCD. 20 participants underwent stress perfusion CMR at baseline, 4 and 24 weeks. 25% had a drop in LVEF to &lt;50% but only 5% had a co-existing LVEF ≥10% from baseline to fulfil criteria for the diagnosis of moderate CTRCD.

Conclusion
BRAF and MEK inhibitor-associated hypertension and CTRCD is common, with a higher incidence in this ‘real world’ prospective cohort than observed in clinical trials. The majority of CTRCD was ‘mild’ and the long term sequalae of this remains unknown. No patients considered to be at low baseline risk for CTRCD using the ESC-recommended risk stratification tool developed moderate or severe CTRCD. These findings support the use of routine blood pressure surveillance in this group as well as baseline risk stratification to guide appropriate imaging surveillance of cardiac function.Figure 1.Schedule of study visitsFigure 2.LV function/CTRCD over time