Table 2.

Associations of Cardiotoxicity Surveillance With Heart Failure During HER2 Targeted Therapy

	Cases (n = 53)	Controls (n = 159)	Crude OR (95% CI)	Adjusted OR (95% CI)
Compliant with LVEF surveillance (at all timepoints)
Yes	33 (62)	92 (58)	1.3 (0.6–2.6)∗	1.2 (0.4–3.9)†
No	20 (38)	67 (42)	1.0	1.0
Compliant with LVEF surveillance (baseline to 6 months)
Yes	33 (62)	96 (60)	1.1 (0.6–2.2)∗	1.0 (0.3–3.1)†
No	20 (38)	63 (40)	1.0	1.0
Compliant with LVEF surveillance (at final surveillance timepoint)
Yes	41 (77)	113 (71)	1.5 (0.7 to 3.2)∗	1.1 (0.3–3.7)†
No	12 (23)	46 (29)	1.0	1.0
Abnormal surveillance LVEF <55% (at any timepoint)
Yes	26 (49)	5 (3)	26.2 (9.6–71.5)‡	27.0 (9.3–78.8)§
No	27 (51)	152 (96)	1.0	1.0
Abnormal surveillance LVEF <55% (at final surveillance timepoint)#
Yes	22 (54)	4 (4)	27.7 (8.8–87.8)‡	25.6 (7.3–90.3)§
No	19 (46)	109 (96)	1.0	1.0

Values are n (%), unless otherwise indicated. Percentages may not add to 100 given rounding.

Abbreviations as in Table 1.

^∗ORs computed with conditional logistic regression. Controls were matched to cases on age, year of treatment, and history of prior or current anthracycline treatment.

^†Odds ratios computed with conditional logistic regression, adjusted for BMI, pre-trastuzumab LVEF, stage of disease (local or metastatic), race, hypertension, calcium channel blocker treatment, and statin treatment.

^‡Firth’s penalized maximum likelihood logistic regression was used to estimate ORs due to the low prevalence of abnormal LVEF among the controls, adjusting for case-control matching factors (age, year of treatment, history of prior or current anthracycline treatment).

^§Firth’s penalized maximum likelihood logistic regression was used to estimate the OR after adjustment for case-control matching factors, BMI, stage of disease, race, hypertension, calcium channel blocker treatment, and statin treatment.

^#This analysis was restricted to 41 case patients and 113 control patients who underwent an LVEF assessment at the final surveillance timepoint.