A 68-year-old woman is referred for evaluation of poorly controlled hypertension. She has a 20-year history of hypertension, which was stable on lisinopril and amlodipine until a year ago. After this, her blood pressure became progressively elevated, requiring the addition of chlorthalidone and carvedilol. Despite this polytherapy, her home readings remain in the 160s/90s. One month ago, she was hospitalized for an episode of acute dyspnea and hypoxia, diagnosed as “flash pulmonary edema”, which resolved rapidly with intravenous diuretics. Her past medical history is significant for coronary artery disease with a stent placed five years ago, hyperlipidemia, type 2 diabetes mellitus, and stage 3 chronic kidney disease. She is a former smoker, having quit 10 years ago.