658: Acute Pulmonary Hypertension Following Right Pneumonectomy in a Lung Cancer Patient: A Case Report

Introduction: Pulmonary hypertension (PH) is defined as a condition characterized by an increased mean pulmonary arterial pressure of 20 mmHg at rest. Pneumonectomy was recently introduced to the PH classifications group 3. It can result in slow deterioration of lung function. We present a case of acute PH after pneumonectomy to contribute to a better understanding of this condition. Description: A 61-year-old male presented to Memorial Sloan Kettering Cancer Center with newly diagnosed right T3N1 non-small cell lung cancer. He received immunotherapy and chemotherapy concurrently with radiation therapy. 6 months later, he underwent a right pneumonectomy with pericardium reconstruction. He developed pericarditis and paroxysmal atrial fibrillation with a rapid ventricular response post-operatively, requiring daily amiodarone. He also experienced hypoxia at rest, necessitating 35% of 40 L/ minute of oxygen (O2) via high-flow nasal cannula (HFNC). An initial transthoracic echocardiogram (TTE) after the surgery showed a pulmonary artery systolic pressure (PASP) < 35 mmHg. While the CT angiogram (CTA) was negative for pulmonary embolism (PE), the repeat TTE 7 days later showed a mild PH with PASP of 41-50 mmHg when the patient was treated with oral steroids for presumed pneumonitis given negative infectious workups. He was later discharged home on 2 L of O2. He came back 2 weeks later with worsened dyspnea and was admitted to the Intensive Care Unit (ICU) due to respiratory failure. Amiodarone was discontinued after one month of usage. A TEE showed PASP > 70 mmHg. He received broad-spectrum antimicrobial coverage; however, infectious workups were negative. A repeat CTA revealed left subsegmental PE without right heart strain, with normal troponin and BNP levels. Due to the high O2 requirement (HFNC 100%) and suspected group 3 and 4 PH, the patient was transferred to another institution’s cardiac ICU for more advanced therapeutic procedures. Discussion: Acute PH following pneumonectomy is rarely reported. The patient described has a suspected acute PH likely from a sudden change in blood flow after the pneumonectomy. Although there were other risk factors, it requires 4-12 months of amiodarone exposure and chronic PE to induce PH. This uncommon case necessitates future studies on pneumonectomy-related PH.