What triggers a hold on therapy with pertuzumab and trastuzumab according to LVEF results?

A hold on therapy with pertuzumab and trastuzumab is indicated when the left ventricular ejection fraction (LVEF) is below 45% or if there is a decrease of 10% from baseline. This monitoring is crucial because both of these medications can lead to cardiac toxicity, particularly in patients with pre-existing heart conditions.

Maintaining LVEF above the specified thresholds helps ensure that the patient’s heart function remains stable and capable of tolerating additional treatment. A decrease in LVEF by 10% from baseline is a significant indicator of declining cardiac function and can prompt the need for further assessment and intervention. The rationale behind this guideline is to prevent potential heart failure or other serious cardiac complications during treatment.

The other choices do not align with current guidelines: an LVEF below 40% or a decrease by 5% might suggest cardiac issues, but do not specifically trigger a hold according to the standard thresholds, which are based on more stringent criteria.