*4.5. Study Limitations*

The major limitation of the study is small sample size due to its single-centre character and, hence, small number of major cardiovascular events, precluding the use of multivariate analysis models. The retrospective observational design of the study may include confounders. This study comes from a tertiary referral centre, one of two leading cardiological centres in Poland performing HTX. Therefore, patients referred to this tertiary referral centre may present with more severe disease than patients usually admitted in other hospitals.

#### **5. Conclusions**

*LMNA* mutation-related cardiac disorders are associated with high and age-dependent penetrance of cardiac manifestations, rapid progression to end-stage HF, and high incidence of life-threatening arrhythmic events. Elevated hsTnT level seems the earliest abnormality emerging in the course of cardiolaminopathies and may facilitate early detection of the *LMNA* carrier status. Circulating cardiac biomarkers, especially increased NT-proBNP level, may be helpful in arrhythmic risk stratification.

**Supplementary Materials:** The following are available online at http://www.mdpi.com/2077-0383/9/5/1443/s1, Figure S1. Receiver-operating characteristic curves used to assess the cutoff points of the biomarkers for prediction of MVA. Figure S2. Highly sensitive troponin T level profiles at baseline and during follow-up visits on a logarithmic scale. Figure S3. N-terminal pro-brain natriuretic peptide level profiles at baseline and during follow-up visits. Table S4. Baseline clinical characteristics of LMNA variant carriers at initial visit according to mutation type. Table S5. Comparison of outcome according to diagnosis at initial visit. Table S6. Clinical characteristics of LMNA variant carriers at last follow-up according to proband status. Figure S7. Kaplan–Meier MVA-free survival curves during follow-up in patients with cardiolaminopathy and no prior history of sudden cardiac arrest or sustained ventricular tachycardia. Figure S8. Kaplan–Meier lifelong HTX-free survival curves in cardiolaminopathy according to proband status. Figure S9. Kaplan–Meier lifelong MVA-free survival curves in cardiolaminopathy according to proband status.

**Author Contributions:** Conceptualization, P.C. and Z.T.B.; data curation, P.C., E.M., M.F., G.T., M.S.-W., and B.F.-N.; formal analysis, P.C., and I.K.; investigation, P.C., E.M., M.F., M.S.-M., G.T., M.S.-W., E.K.B., B.F.-N., M.L., A.O., M.B., M.K., F.T., J.G., T.Z., R.P., and Z.T.B.; methodology, P.C., E.M., I.K., R.P., and Z.T.B.; project administration, Z.T.B.; supervision, R.P. and Z.T.B.; visualization, P.C., I.K., and G.T.; writing—original draft, P.C., I.K., G.T., and Z.T.B.; writing—review and editing, P.C., E.M., I.K., M.F., M.S.-M., G.T., M.S.-W., E.K.B., B.F.-N., M.L., A.O., M.B., M.K., F.T., J.G., T.Z., R.P., and Z.T.B.. All authors have read and agreed to the published version of the manuscript.

**Funding:** The work of P.C., G.T., and Z.T.-B. was supported by NCBiR ERA-CVD DETECTIN-HF/2/2017 IB.4/II/17 grant.

**Conflicts of Interest:** The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.
