Untreated NAFLD may have significant consequences including an increase in mortality and cardiovascular injury. Thus, early detection of NAFLD is currently believed not only to prevent liver related but also cardiovascular mortality. However, almost nothing is known about the relevance of co-existing NAFLD in patients with angiographically validated coronary artery disease (CAD).
We investigated the impact of NAFLD in a large cohort of patients that had been referred to coronary angiography. Modelling the common NALFD and fibrosis scores FIB-4 and NFS as splines revealed significant associations with all-cause and cardiovascular mortality when the Cox regression models were only adjusted for cardiovascular risk factors that were not already included in the calculation of the scores. Stratifying the scores into quartiles yielded hazard ratios (95 % CI) for all-cause and cardiovascular mortality for the 4th quartile vs the 1st quartile of 2.28 (1.90-2.75) and 2.11 (1.67-2.67) for FIB-4 and of 3.21 (2.61-3.94) and 3.12 (2.41-4.04) for NFS.
However, we did not observe an independent association of FIB-4 or NFS with cardiovascular mortality in our prospective CAD cohort after full adjustment for all cardiovascular risk factors. Regarding all-cause mortality, the spline model remained significantly associated while the model using quartiles was not.
To further validate these observations, we restricted this analysis to a cardiovascular (CV) high-risk group of 2215 patients with more than 20 % luminal narrowing of a coronary artery as confirmed by coronary angiography. Again, even in these CV high-risk profile patients, NAFLD relevant scores did not predict cardiovascular mortality. Also, neither NFS nor FIB-4 were useful as prognostic models for primary prevention of cardiovascular events.
In summary, our results from a well-defined, prospective CAD as well as from a defined high CV risk subgroup demonstrated that concomitant NAFLD was not an independent predictor of cardiovascular mortality.
