Background:Hydroxychloroquine (HCQ) cardiotoxicity remains an underrecognized condition. Diagnosis ultimately relies on invasive endomyocardial biopsy (EMB) and non-invasive screening methods are warranted. Strain imaging is a novel tool to detect early subclinical left ventricular (LV) dysfunction and may have a role in screening for HCQ cardiotoxicity (1). Strain measures systolic deformation indices that when decreased can predict cardiovascular outcomes more accurately than LV ejection fraction (2).Objectives:We assessed whether high HCQ cardiotoxicity risk is associated with a specific strain pattern in a group of patients with SLE and end-stage renal disease (ESRD).Methods:This was a retrospective study in a tertiary care center in New York on a group of patients with an established diagnosis of SLE, ESRD and cardiomyopathy on the index echocardiogram followed between years 2003 and 2019. The patients were stratified into two groups: high risk HCQ toxicity group was defined as either cumulative HCQ dose ≥1000g and/or an endomyocardial biopsy confirming HCQ toxicity. Low/moderate risk group was defined as a cumulative dose of HCQ <1000g. Clinical, demographic, electrocardiographic and echocardiographic strain parameters were compared between the groups.Results:A total of 16 patients were included. Two patients had EMB consistent with HCQ induced toxicity and 3 patients had cumulative HCQ doses ≥1000g. There were no significant differences in the baseline demographic characteristics between the two groups. Compared to patients with low/moderate risk, patients in the high risk group had a lower heart rate at the time of the echocardiogram (69 vs 87 beats per minute, p=0.08) and a higher frequency of LV hypertrophy (40% vs 9.1%, p=0.2). Strain analysis showed that both groups had compromised LV global longitudinal strain (GLS) and global cross-sectional strain (GCS). However, compared to the low/moderate risk group, the high risk group had a weaker LV GLS (-12.3% vs -14.9%, p=0.27).Characteristics overall and stratified by HCQ risk groupCharacteristicOverall (n=16)Low/Moderate HCQ Risk(n=11)High HCQ Risk and/or Positive EMB (n=5)P valueDemographicsAge, years47.5 (36.5,60.7)50.0 (33.9,60.5)42.5 (42.7,61.0)0.95Female, n(%)14 (87.5)9 (90)5 (83.3)0.99Clinical FeaturesSLE duration, years7.4 (4.3,17.5)5.5 (3.5,13.2)15.6 (11.6,19.3)0.15HCQ cumulative dose, g422.8 (224.2,422.8)285.4 (110.8,523.6)1140 (1006,1625.4)0.005HCQ therapy duration, years3.4 (2.5, 8.9)3.2 (1.5,5.1)7.8 (6.8,11.6)0.06HCQ daily dose, mg/d226 (200,394.9)200 (179.4,253.7)400 (389.8,400)0.007Hypertension, n (%)14 (87.5)10 (90.9)4 (80.0)0.99Diabetes, n (%)3 (18.8)2 (18.8)1 (20.0)0.99CAD, n (%)3 (18.8)2 (18.8)1 (20)0.99EchocardiogramEF, %55 (42.5,60)55 (40,60)55 (55,70)0.45LA size, cm3.8 (3.4,4.3)3.8 (3.4,4.2)4.3 (3.4,4.9)0.30LVEDD, cm4.9 (4.4, 5.5)4.8 (4.2,5.5)5.0 (4.9,5.4)0.43E/E’12.3 (8.8,16.3)12 (8.8,14.9)16.9 (4.9,21.8)0.43Moderate-severe LV hypertrophy, n(%)3 (18.7)1 (9.1)2 (40.0)0.20Strain echocardiographyGLS, %-13.9 (-16.7,-12.3)-14.9 (-16.7,-12.9)-12.3 (-15.4,-12.2)0.27Base/Apex Ratio0.8 (0.7,0.9)0.76 (0.68,0.86)0.76 (0.66,0.83)0.95GCS, %-20.2 (-21.7,-17)-19.7 (-20.5,18.0)-21.7 (-23.9,-20.9)0.16RV GLS, %-20.19 (-22.1,-17.5)-20.2 (-22.3,-17.1)-19.8 (-22.1,-17.5)0.99Conclusion:We report an association of higher HCQ cardiotoxicity risk and impaired strain in a set of SLE ESRD patients. Standard echo measures did not differentiate between high and low/moderate risk patients. Although the findings did not reach statistical significance, given the small sample size, results are still suggestive of a possible utility of strain echocardiography for detection of early HCQ toxicity.References:[1]Buss SJ, et al. J Rheumatol. 2010;37(1):79-86[2]Kalam K, et al. Heart. 2014;100(21):1673-80Disclosure of Interests: None declared