Prevalence and nature of dyspnea in patients with hereditary hemorrhagic telangiectasia (HHT)
Hereditary hemorrhagic telangiectasia (HHT) is a vascular disorder associated with pulmonary AVMs (PAVMs), present in about 30-50% of patients. Dyspnea is frequently reported by about one-half of patients with PAVMs and has been related to the degree of right to left shunting. However, many HHT patients with PAVMs remain asymptomatic and those without PAVMs have been observed to have dyspnea, the cause of which has not been characterized. The study objectives were to determine the prevalence of dyspnea and its etiology in the HHT population. Retrospective review of over 1000 patients at an HHT Center of Excellence from 1997 to 2010. Patients were categorized as definite HHT if they met ≥3 clinical diagnostic criteria or had a positive genetic diagnosis. Patients were unlikely to have HHT (non-HHT) if they had 1 or fewer diagnostic criteria. Data on dyspnea prevalence (MMRC ≥ 1), PAVMs, underlying cardio-pulmonary disease, symptomatic liver venous malformations, anemia and obesity was reviewed. 506 patients were categorized as having HHT, of which 202 (40%) had confirmed PAVMs. Dyspnea prevalence was 35% (178/506) vs. 18% (50/284, p < 0.0001) in the HHT and non-HHT patients, respectively. With multivariable logistic regression, the odds of dyspnea (MMRC ≥1) was 3.45 (95% CI 2.08-5.71) with the presence of PAVMs in HHT patients. Other independent predictors of dyspnea were older age, underlying cardio-pulmonary disease, anemia, and obesity. Prevalence of dyspnea is significant, evident in about one-third of HHT patients, often associated with PAVMs. It is important to consider other etiologies for dyspnea when assessing patients with HHT.