Data accuracy, consistency and completeness of the national Swiss cystic fibrosis patient registry: Lessons from an ECFSPR data quality project.

BACKGROUND: Good data quality is essential when rare disease registries are used as a data source for pharmacovigilance studies. This study investigated data quality of the Swiss cystic fibrosis (CF) registry in the frame of a European Cystic Fibrosis Society Patient Registry (ECFSPR) project aiming to implement measures to increase data reliability for registry-based research. METHODS: All 20 pediatric and adult Swiss CF centers participated in a data quality audit between 2018 and 2020, and in a re-audit in 2022. Accuracy, consistency and completeness of variables and definitions were evaluated, and missing source data and informed consents (ICs) were assessed. RESULTS: The first audit included 601 out of 997 Swiss people with CF (60.3 %). Data quality, as defined by data correctness ≥95 %, was high for most of the variables. Inconsistencies of specific variables were observed because of an incorrect application of the variable definition. The proportion of missing data was low with <5 % for almost all variables. A considerable number of missing source data occurred for CFTR variants. Availability of ICs varied largely between centers (10 centers had >5 % of missing documents). After providing feedback to the centers, availability of genetic source data and ICs improved. CONCLUSIONS: Data audits demonstrated an overall good data quality in the Swiss CF registry. Specific measures such as support of the participating sites, training of data managers and centralized data collection should be implemented in rare disease registries to optimize data quality and provide robust data for registry-based scientific research.

First experience in Switzerland in Phe508del homozygous cystic fibrosis patients with end-stage pulmonary disease enrolled in a lumacaftor-ivacaftor therapy trial - preliminary results.

AIMS OF THE STUDY: Cystic fibrosis is the most common genetic disorder in Caucasians. The combination of the cystic fibrosis transmembrane conductance regulator (CFTR) corrector lumacaftor / potentiator ivacaftor (LUM/IVA) has been shown to increase forced expiratory volume in 1 second (FEV1) moderately, but predominantly reduce acute exacerbation rate (AER) in Phe508del homozygous cystic fibrosis patients; however, patients with FEV1 <40% predicted were excluded from studies. We used LUM/IVA on a "compassionate use" basis in cystic fibrosis patients with end-stage pulmonary disease. Our aim was to evaluate if this patient cohort tolerates LUM/IVA treatment and if there is clinical stabilisation. Lung transplantation (LTX) is the ultimate treatment option for these patients despite maximal therapy. If LTX candidates stabilise clinically, conditions for LTX, when it is indicated, improve. This is particularly important in countries such as Switzerland with a low organ donation rate and long waiting times for suitable donor organs. METHODS: We included all patients from the Adult Cystic Fibrosis Centre at the University Hospital Zurich with Phe508del homozygous genotype and a predicted FEV1 <40% or being evaluated or already listed for LTX. Clinical outcome data comprised AER, 6-minute walking distance (6-MWD), FEV1, forced vital capacity (FVC), mid-expiratory flow (MEF 25-75%), sweat chloride, body mass index (BMI) and quality of life. Respiratory-related adverse events (RAEs) were recorded. LUM/IVA treatment was initiated at a low dose and the dose increased stepwise. RESULTS: Twenty patients were on trial with LUM/IVA; at the cut-off date, 6-month follow-up was complete for 10 patients. RAEs were severe and occurred early. The dropout rate due to RAE or lack of clinical success was 20%. Median AER decreased from 2.5 in the 6 months pre-treatment to 1 during the observation period. FEV1 increased from 32 to 34.5% predicted, p = 0.292. The 6-MWD increased by a median 33 m (p = 0.6086). Sweat chloride decreased significantly by a median of 25 mmol/l (p = 0.0003). Median BMI increased from 19 to 19.9 kg/m2 (p = 0.1488). At the cut-off, three previously listed patients were paused on the transplant waiting list. CONCLUSION: Phe508del homozygous cystic fibrosis patients with end-stage pulmonary disease tolerated LUM/IVA, although RAEs occurred early and were severe. This positive finding was probably due to the stepwise dose increases. There was clinical benefit mainly from reduction in AER and stabilisation of lung function. We propose that all suitable Phe508del homozygous cystic fibrosis patients with end-stage pulmonary disease should have a trial of LUM/IVA treatment in experienced centres.

Coronary artery disease in lung transplant candidates: role of routine invasive assessment.

BACKGROUND: An atherosclerotic disease burden sufficient to put lung transplant candidates at risk for end-organ disease after transplantation is considered to be a relative contraindication for lung transplantation. OBJECTIVES: The aim of this study was to assess our current practice of cardiac workup by coronary angiography in lung transplant candidates ≥50 years of age. METHODS: We retrospectively analyzed 50 consecutive lung transplant candidates ≥50 years of age in which coronary angiography was performed at the University Hospital Zurich (2009-2013). For every patient, the risk of developing an acute coronary event was estimated by using a recalibrated version of the PROCAM study calculator for the Swiss population. RESULTS: The median estimated risk of developing an acute coronary event within 10 years in the study cohort (n = 50) was 4.2% (interquartile range 1.9-7.6), which is considered to be a low risk. Sixteen percent of patients were considered to be at intermediate risk. In 66% of patients, coronary angiography showed no coronary artery disease (CAD). In 28% of patients, CAD without significant stenosis was diagnosed. In 6% of patients, significant coronary stenosis was detected requiring percutaneous coronary intervention. No correlation between the coronary status and the risk score or cardiovascular risk profile was found. CONCLUSIONS: The high prevalence of asymptomatic CAD in lung transplant candidates without correlation to a common clinical risk score supports the important role of coronary angiography for the assessment of coronary artery status. This approach might prevent cardiovascular events and improve long-term survival after transplantation.