Incidence and evolution of carcinoid syndrome in the heart

Carcinoid syndrome originates from carcinoid tumors localized in the gastrointestinal system, pancreas, biliary vessels, bronchi, ovaries and testes. The condition is characterized by flushing, telangiectasias, diarrhea, bronchoconstriction and cardiac involvement, while cardiac lesions may occur in 50% of patients. This study aimed to investigate-non-invasively-the frequency, severity and evolution of carcinoid heart involvement.

Among 87 patients with carcinoid syndrome undergoing routine echocardiography, 39 (45%) had cardiac involvement; 36 of these had thickened, shortened, immobile tricuspid leaflets. Tricuspid regurgitation was present in all 36, it was moderate or severe in 22. Pressure half-time rose to 117 +/- 35 ms, implying mild tricuspid stenosis. The pulmonary valve was also thickened, retracted and immobile with stenotic appearance in 19 patients; regurgitation was present in 16, and mild in 11. Nine patients had pericardial effusion. Of 39 patients with cardiac lesions, 18 had at least one follow up study within 16 +/- 7 months; in 15 cases the valve lesions deteriorated. Tricuspid regurgitation became more severe in six and pressure half-time rose from 107 +/- 46 to 132 +/- 50 ms. Pulmonary regurgitation deteriorated in two, while three patients had new pulmonary valve involvement. The peak gradient across the pulmonary valve increased from 18 +/- 7 to 25 +/- 9 mmHg. Twenty-two patients without heart involvement in the first examination had a follow up study (19 +/- 5 months) during which seven developed valvular lesions, with four moderate and three mild tricuspid regurgitation; mild stenosis was present in all cases. Two patients with mild tricuspid regurgitation had mild mixed pulmonary valve involvement, while of those with moderate tricuspid regurgitation, one also had moderate pulmonary stenosis with mild regurgitation. Five patients with both tricuspid and pulmonary valve diseases had interventional treatment: three underwent balloon valvuloplasty on both valves simultaneously due to stenotic lesions but later relapsed; the other two underwent double valve replacement with biological prostheses but in both cases the pulmonary valve developed severe destruction leading to one death. The other four patients survived for 36, 41, 25 and 16 months, respectively.

Right valvular heart disease occurs frequently in patients with carcinoid syndrome. Evolution of lesions is rapid, leading to right heart failure, though death usually occurs from progressive systemic disease and rarely from pulmonary stenosis. Surgery is the most effective treatment and balloon valvulotomy is only palliative. However, therapy of the systemic condition is predominantly the treatment of choice.