Our patient is a 67-year-old white man, who works as a teacher in a small city. He does not smoke tobacco; he has a history of arterial hypertension grade I to II and coronary heart disease. His mother died from myocardial infarction due to occlusive coronary artery disease. He was diagnosed as having CML in 2006. The treatment was initially started with imatinib (Glivec, Novartis) 400 mg administered orally once daily. Imatinib 400 to 800 mg per day was taken for 53 months. He lost major molecular response (MMR) and imatinib therapy was replaced with dasatinib 100 mg orally administered once daily and after 6 months MMR was achieved. He was also using torasemide 20 mg orally administered once daily and metoprolol succinate 50 mg orally administered once daily. In April 2015 he developed increasing dyspnea on exertion, fatigue, and peripheral edema. He consulted his family physician, and a chest X-ray was done, confirming pleural effusion. On admission his heart rate was 97 beats per minute and blood pressure was 143/90 mmHg. Fever was not present. He presented with peripheral edema and diminished breath sounds. Pleural friction rub was present. Deformity of the spine accompanied by lower back pain was noted during neurological check-up. The pleural fluid was drawn out several times via thoracentesis (1.5 to 2 liters of exudate in total) but cytological analysis excluded malignancy, a GeneXpert® tuberculosis test of a bronchial smear was also negative, therefore, the pleural effusion was suspected to be caused by congestive heart failure. A complete blood count was normal, but his creatinine levels were elevated (Tables and ). Over the course of the next 4 months his general condition deteriorated as he experienced multiple recurrences of pleural effusion requiring drainage of the built-up fluid (Table ). Dasatinib therapy was stopped in September 2015 after 42 months of treatment. A coronarography was done in September 2015; it did not reveal any hemodynamically important stenosis in his coronary arteries, thereby excluding coronary artery disease. An echocardiogram showed right ventricular dilation, estimated right ventricle systolic pressure of 125 mmHg, and severe tricuspid regurgitation suggesting PH.\nRHC performed on 12 October 2015 revealed severe PAH with mPAP of 53 mmHg and normal left ventricle diastolic pressure (Table ). A computed tomography scan confirmed the absence of pulmonary embolism; laboratory specific tests for HIV, rheumatoid factor, and anti-nuclear antibodies (ANA) were negative and dasatinib-induced PAH was diagnosed. The 6-minute walk test (6MWT) distance was limited to 165 m (Table ). He started PAH-targeted treatment with sildenafil 20 mg × 3 orally administered and restarted CML therapy with imatinib 400 mg orally administered daily on 19 October 2015.\nHis condition rapidly improved, a check-up RHC done a month later showed mPAP of 34 mmHg, decreased pulmonary vascular resistance, and increased cardiac output values (Table ). His 6MWT score was 2.1 times higher (Table ). Echocardiography done in February 2016 revealed right ventricle systolic pressure of 50 mmHg; a complete blood count and biochemistry showed no abnormalities (Tables and ). He has been asymptomatic since, but treatment for PAH with sildenafil is still necessary. The last hematological check-up was in January 2017, he was still on imatinib 400 mg daily and had normal complete blood count and MMR (BRA-ABL was negative).
A 52-year-old male patient was diagnosed with CP CML in 2001. He was initially treated with interferon-alpha and later received a daily regimen of 400 mg imatinib that was dose-adjusted over time because of AEs. He had pleurisy of unknown origin during his teenage years. Because no cytogenetic response was achieved on imatinib, dasatinib was initiated at a dose of 140 mg daily from December 2, 2005 and was initially well tolerated.\nHowever, in February 2008, the patient complained of intermittent NYHA class II dyspnea on effort, and his chest radiograph revealed right PE; with sustained dasatinib treatment, the symptom progressed to NYHA class III on February 24, 2009. At that time, dasatinib was discontinued, and treatment with low dose sildenafil (25 mg/day) was initiated. One month after dasatinib discontinuation, a chest radiograph revealed a nearly resolved state. However, a chest computed tomography scan revealed mild pulmonary congestion, and a transthoracic Doppler echocardiogram showed an increased RVSP of 71 mm Hg and a small amount of pericardial effusion. BNP levels were elevated to 263 pg/mL. Laboratory tests for human immunodeficiency virus (HIV) and rheumatic diseases, including antinuclear antibodies, antibodies to double-stranded DNA, and anti-Scl-70 antibodies, were negative. A careful review of concurrent medications or toxins suspected to play an essential role in the development of PAH revealed no causative evidence.\nAfter switching to nilotinib (800 mg/day) in May 2009, the patient’s subjective dyspnea improved, and his RVSP decreased to 55 mm Hg. BNP levels returned to 28 pg/mL, and the 6-minute-walk test value improved from 480 m to 615 m. The patient intermittently discontinued nilotinib because of repeated hyperbilirubinemias and was transferred to our hospital in July 2009. Eighteen months later, he lost cytogenetic response with an E292V mutation; therefore, a daily dose of 100 mg dasatinib was reintroduced in December 2010. Although the patient previously experienced dasatinib-associated PAH, we chose to administer dasatinib in order to overcome the patient’s mutation-related resistance. The dose of dasatinib (40-60 mg/day) was then adjusted according to the severity of dyspnea, and a major cytogenetic response on dasatinib was maintained.\nAfter dasatinib administration, the patient again experienced a sustained NYHA functional class II dyspnea with serial elevation of left ventricular systolic pressure observed in a follow-up echocardiogram (). On April 11, 2011, a daily dose of 45 mg ponatinib was prescribed without improvement in PAH while maintaining a complete cytogenetic response and a major molecular response. In August 2012, the patient's subjective dyspnea was improved to NYHA functional class I. The changes in clinical course, cardiopulmonary parameters and treatment history are depicted in and .