Bronchiectasis is associated with coronary artery calcification even in never smokers.

A recent publication in Respirology examined the relationship between cardiovascular disease and airways disease, demonstrating that patients who had a cardiovascular event following a moderate- or severe exacerbation of asthma had a higher risk of mortality.1 The patients were older, and although age was adjusted for in the analysis, the presence of smoking was not reported. Cardiovascular disease and major adverse cardiovascular events (MACE) are also common in patients with bronchiectasis.2 All-cause mortality increases with increasing severity of bronchiectasis. Some of this increase in mortality may be related to cardiovascular disease. Coronary artery calcium (CAC) is associated in a graded fashion with the risk of atherosclerotic cardiovascular disease and MACE, independent of traditional risk factors.3 Since many patients with bronchiectasis have chest CTs for diagnosis, disease monitoring and assessment of acute exacerbations, CAC scoring could provide opportunistic cardiac risk assessment and risk reduction to this cohort of patients. Recent international guidelines4 suggest routine reporting of CAC on all non-gated non-contrast CT chest examinations. In the era of lung cancer screening it is likely that we will detect CAC in patients with both asthma and bronchiectasis. The standardization of reporting of chest CTs to include CAC could be an opportunity for expanding CAC as a marker of comorbidity in a ‘treatable traits’ approach to reducing mortality risk for patients with airways disease. We retrospectively measured CAC on CT scans of 155 patients (108 females, mean age 66 ± 16 years) in the Australian Bronchiectasis Registry. Patients were stratified in terms of risk categories (nil, mild, moderate or severe) based on CAC quantification. Bronchiectasis severity was calculated using the FACED score. Somers' delta test was used to assess the association between FACED and CAC score. Bronchiectasis severity was mild in 49%, moderate in 38% and severe in 13%. Most patients (61%) had evidence of coronary calcification (27% mild, 20% moderate and 14% severe calcification). There was no difference in cardiovascular comorbidity or medications between patients with varying bronchiectasis severity. The rate of smoking was significantly higher in patients with higher CAC and FACED scores. There was a positive association between FACED score and CAC risk score, d = 0.259, p = 0.001 (Figure 1). This remained significant when stratified for smoking status. Bronchiectasis severity is associated with increased coronary artery calcium, and therefore cardiac risk, even in never-smokers. We were surprised that this association was not stronger given the fact that severity of bronchiectasis using FACED criteria is strongly correlated with exacerbation frequency and systemic inflammation. It is worth noting that only a minority of patients (13%) had severe bronchiectasis, which may have led to an underestimation of the impact of bronchiectasis severity and inflammation on cardiac risk. Despite having non-severe bronchiectasis, most patients had evidence of CAC which indicates an independent increase in cardiovascular risk that we can easily and non-invasively measure. This represents a significant population of patients with bronchiectasis who would be anticipated to benefit from early initiation of cardioprotective treatment and subsequent risk reduction. Lewis Holmes: Conceptualization (equal); data curation (lead); formal analysis (lead); investigation (equal); methodology (equal); project administration (equal); writing – original draft (lead); writing – review and editing (lead). Isaac Lui: Data curation (equal); formal analysis (equal); investigation (equal); methodology (equal); writing – original draft (supporting); writing – review and editing (equal). Paul Lilburn: Conceptualization (equal); data curation (equal); methodology (equal); project administration (equal); writing – review and editing (equal). Christopher Naoum: Investigation (equal); methodology (equal); writing – review and editing (equal). Leonard Kritharides: Methodology (equal); supervision (equal); writing – review and editing (equal). Lloyd Ridley: Formal analysis (equal); investigation (equal); methodology (equal); project administration (equal); supervision (equal); writing – review and editing (equal). Lucy Morgan: Conceptualization (lead); data curation (lead); formal analysis (equal); funding acquisition (equal); investigation (equal); methodology (equal); project administration (equal); supervision (lead); writing – original draft (equal); writing – review and editing (equal). Lucy Morgan receives speaking fees from Zambon, Insmed, AstraZeneca, Novartis and GSK and grant funding from Boehringer Ingelheim, Novartis and AstraZeneca. Leonard Kritharides receives consulting fees from Seqirus and speaking fees from Novartis and Limbic. Lloyd Ridley receives speaking fees from AstraZeneca. The other authors report no significant conflicts of interest relating to this manuscript. The Australian Bronchiectasis Registry where the data was collected from has National research ethics approval (Protocol No. X16-0382, Project No. HREC/15/CRGH/225). Further approval for this study was obtained from the local institutional review board CH62/6/2018-209. The data that support the findings of this study are available from the corresponding author upon reasonable request.