Evaluation of Hypertension Management and Cardiovascular Adverse Event Prevention in Patients With B-cell Malignancies Undergoing Treatment With Bruton Tyrosine Kinase Inhibitors, the HALT Study

This study (HALT) is tracking how high blood pressure and heart complications develop in people with certain blood cancers — including chronic lymphocytic leukemia (CLL), mantle cell lymphoma, Waldenstrom macroglobulinemia, and marginal zone lymphoma — who are starting treatment with a class of drugs called BTK inhibitors. The goal is to better understand and potentially prevent cardiovascular side effects of these cancer therapies. **You may be eligible if...** - You have been diagnosed with CLL, mantle cell lymphoma, Waldenstrom macroglobulinemia, or marginal zone lymphoma - You are about to start a BTK inhibitor medication (either as a first-time user or switching to a new BTK inhibitor) - You are willing and able to return to the participating clinic for ongoing follow-up **You may NOT be eligible if...** - Your blood cancer has spread to the brain or spinal fluid (central nervous system involvement) Talk to your doctor to see if this trial is right for you.