Interaction of Hypertension and Diabetes Mellitus on Post-Cardiac Arrest Treatments and Outcomes in Cancer Patients Following Out-of-Hospital Cardiac Arrest.

: Out-of-hospital cardiac arrest (OHCA) is associated with high mortality, and outcomes may be influenced by underlying conditions such as cancer, hypertension (HTN), and diabetes mellitus (DM). This study aimed to evaluate whether HTN and DM modify the effects of post-resuscitation treatments-specifically targeted temperature management (TTM) and percutaneous coronary intervention (PCI)-on survival and neurological recovery in OHCA patients with a history of cancer. : This retrospective cohort study analyzed data from the Korean national OHCA registry between January 2018 and December 2021. Adults aged ≥18 years with presumed cardiac-origin OHCA and a documented history of cancer-defined as any prior cancer diagnosis recorded in medical records regardless of remission status-were included. Multivariable logistic regression was used to examine associations between treatment and outcomes, and interaction effects were assessed using adjusted -values to account for multiple testing. : Among the 124,916 EMS-assessed OHCA cases, 4115 patients met the inclusion criteria. TTM and PCI were both statistically associated with good neurological recovery (TTM: adjusted odds ratio [aOR], 1.69; 95% confidence interval [CI], 1.12-2.55; < 0.05; PCI: aOR, 11.35; 95% CI, 7.98-16.14; < 0.05). In interaction analyses, the benefit of TTM and PCI for achieving good neurological recovery was attenuated in patients with diabetes mellitus (DM; TTM: aOR, 0.59; 95% CI, 0.23-1.49; PCI: aOR, 4.94; 95% CI, 2.69-9.06) and hypertension (HTN; TTM: aOR, 0.94; 95% CI, 0.49-1.82; PCI: aOR, 7.47; 95% CI, 4.48-12.44), with adjusted -values < 0.05 for all interactions. : In OHCA patients with a history of cancer, TTM and PCI are associated with improved survival and neurological outcomes. However, the presence of comorbidities such as HTN and DM may attenuate these benefits. These findings support the need for individualized post-resuscitation care strategies that account for comorbid conditions.