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The pathogenesis of Takotsubo Cardiomyopathy (TTCM) remains unknown. Several case reports have described the occurrence of TTCM in patients with preexisting valvular heart disease (VHD). We sought to examine the association between preexisting VHD and TTCM in hospitalized patients.
Using the Healthcare Cost and Utilization Project (HCUP) Nationwide Inpatient Sample (NIS), all hospitalizations between 2007 and 2011 with preexisting diagnosis of VHD and admitting diagnosis of TTCM were extracted using ICD-9 CM codes. We compared patients admitted for TTCM who had preexisting VHD to those without. We excluded patients below the age of 18 as well as those diagnosed with TTCM who later underwent percutaneous coronary intervention (PCI). Multivariate logistic regression was used to assess the independent effect of preexisting VHD on both occurrence of TTCM and clinical outcomes (length of stay (LOS), stroke and in-hospital mortality).
In our study, 613 (0.06%) out of the 1,084,719 hospitalized patients with preexisting VHD, had TTCM, compared to 13,381 (0.04%) out of the 31,460,000 with no preexisting VHD (p<0.0001). In adjusted models, patients with preexisting VHD had a lower risk of being hospitalized for TTCM in the index hospital admission (adjusted odds ratio (aOR) =0.83, 95% confidence interval (CI) =0.77-0.90), independent of potential demographic, comorbid and lifestyle confounders. However, preexisting VHD was significantly associated with longer LOS (aOR=2.59, 95% CI=1.95-3.23), increased stroke rate (aOR=2.49, 95% CI=1.75-3.54) and higher in-hospital mortality (aOR=1.48, 95% CI=1.05-2.09).
In this large, nationwide study, preexisting VHD was associated with worse clinical outcomes in patients hospitalized for TTCM. Our results can guide future clinical decision-making regarding prompt risk factor identification for poor prognosis in TTCM patients. Future prospective studies are needed to further evaluate this association.