Takotsubo syndrome and stroke risk: A nationwide register-based study.

AIMS: Previous small-scale studies have indicated a short-term stroke incidence of 1.0-1.3% following Takotsubo (syndrome). In this nationwide register-based study, we investigated the 90-day risk of ischemic stroke (IS) or transient ischemia attack (TIA) and mortality of patients with Takotsubo. METHODS AND RESULTS: Patients with incident Takotsubo between January 1st 2009 to September 30th 2018 were identified from Danish nationwide registries. Takotsubo patients were age- and sex-matched with background-, atrial fibrillation/flutter- (AF) and myocardial infarction (MI) cohorts. Cumulative incidences and Cox proportional-hazard regression models were used to analyze the following outcomes: 1) composite of IS/TIA and 2) all-cause mortality. A total of 890 patients with Takotsubo were followed for 90 days. The cumulative 90-day incidence of IS/TIA in the Takotsubo-, background-, AF- and MI cohort, was 2.1% (n = 19), 0.1% (n = 4), 1.1% (n = 47) and 1.5% (n = 66), respectively. The cumulative 90-day mortality in the Takotsubo-, background-, AF- and MI cohort was 5.1% (n = 45), 0.3% (n = 13), 1.7% (n = 75) and 5.6% (n = 230), respectively. The adjusted hazard ratio (HR) for 90-day IS/TIA was when compared to the background-, AF- and MI cohort, 26.43 (95% CI: 8.82-79.24), 1.91 (95% CI: 1.09-3.35) and 2.06 (95% CI: 1.12-3.79), respectively. The adjusted HR for 90-day mortality was when compared to the background-, AF- and MI cohort, 14.19 (95% CI: 7.43-27.09), 0.73 (95% CI: 0.52-1.02) and 1.96 (95% CI: 1.25-3.07), respectively. CONCLUSION: Patients with Takotsubo had an increased 90-day hazard for IS/TIA when compared to age- and sex-matched background-, AF- and MI cohorts.

Long-term Risk of Death and Hospitalization in Patients With Heart Failure and Takotsubo Syndrome: Insights From a Nationwide Cohort.

BACKGROUND: Data concerning the long-term risk of heart failure (HF) in patients with takotsubo syndrome (TTS) are sparse. We compared the rates of death and hospitalization due to HF with matched individuals from the background population and patients with ST-segment elevation myocardial infarction (STEMI). METHODS: In this nationwide observational cohort study, all patients with first-time TTS (2011-2018) who were alive at discharge were identified by using data from Danish nationwide registries. These were matched for age and sex with individuals from the background population (1:4 matching) and with patients with STEMI who were alive at discharge (1:3 matching). RESULTS: A total of 881 patients with TTS who were alive at discharge were identified (median age 70 years; 89.4% men). During a mean follow-up of 2.9 years, the incidence rates of death, HF hospitalization, and TTS recurrence in survivors of TTS were 6.9, 0.9 and 1.1 events per 100 person-years. The corresponding absolute 3-year risks were 9.3%, 1.8% and 2.5%, respectively. Survivors of TTS had higher associated rates of death compared with the background population (hazard ratio [HR] 2.05 [95% CI, 1.62-2.60]) and survivors of STEMI (HR 1.69 [1.34-2.13]). Similarly, survivors of TTS had higher associated rates of hospitalization due to HF compared with the background population (HR 4.24 [1.88-9.53]), but lower rates compared with survivors of STEMI (HR 0.34 [0.20-0.56]). Propensity-score matched analyses yielded similar results. CONCLUSIONS: Survivors of TTS had significantly higher associated mortality rates than the background population and survivors of STEMI. Survivors of TTS had lower HF hospitalization rates than survivors of STEMI, but the rates were higher than those of the background population.

Na+,HCO3--cotransporter NBCn1 (Slc4a7) accelerates ErbB2-induced breast cancer development and tumor growth in mice.

Metabolic acid production challenges cellular pH homeostasis in solid cancer tissue, and mechanisms of net acid extrusion represent promising new targets for breast cancer therapy. Here, we used genetically engineered mice to investigate the contribution of the Na+,HCO3--cotransporter NBCn1 (Slc4a7) to intracellular acid-base regulation in ErbB2-induced breast cancer tissue and the consequences of NBCn1 knockout for breast tumor development and growth. We demonstrate an approximately 2-fold increase of NBCn1 protein abundance in ErbB2-induced breast cancer tissue compared to normal breast tissue despite a 4-fold decrease in the NBCn1 mRNA level. In congruence, we show that NBCn1 facilitates net acid extrusion and elevates steady-state intracellular pH in breast cancer tissue. Disruption of NBCn1 expression delayed ErbB2-induced breast carcinogenesis from a median tumor-free survival of 9.5 months in wild-type mice to 12 months in NBCn1-knockout mice and decelerated the tumor growth rate by approximately 1/3. Glycolytic metabolism-evaluated based on the interstitial concentrations of lactate and glucose measured in microdialysates-was increased in breast cancer tissue compared to normal breast tissue, but was unaffected by NBCn1 knockout. Disruption of NBCn1 expression inhibited cell proliferation-evaluated by staining for the proliferative marker Ki67-particularly in central tumor areas with predicted increase in acid loading from glycolytic metabolism. In conclusion, NBCn1 regulates intracellular pH in ErbB2-induced breast cancer tissue by providing a pathway for cellular uptake of HCO3-, which can neutralize metabolic acidic waste products. Disrupting NBCn1 expression delays ErbB2-induced breast cancer development, inhibits cancer cell proliferation, and decelerates tumor growth.

Murine breast cancer feed arteries are thin-walled with reduced α1A-adrenoceptor expression and attenuated sympathetic vasocontraction.

BACKGROUND: Perfusion of breast cancer tissue limits oxygen availability and metabolism but angiogenesis inhibitors have hitherto been unsuccessful for breast cancer therapy. In order to identify abnormalities and possible therapeutic targets in mature cancer arteries, we here characterize the structure and function of cancer feed arteries and corresponding control arteries from female FVB/N mice with ErbB2-induced breast cancer. METHODS: We investigated the contractile function of breast cancer feed arteries and matched control arteries by isometric myography and evaluated membrane potentials and intracellular [Ca2+] using sharp electrodes and fluorescence microscopy, respectively. Arterial wall structure is assessed by transmission light microscopy of arteries mounted in wire myographs and by evaluation of histological sections using the unbiased stereological disector technique. We determined the expression of messenger RNA by reverse transcription and quantitative polymerase chain reaction and studied receptor expression by confocal microscopy of arteries labelled with the BODIPY-tagged α1-adrenoceptor antagonist prazosin. RESULTS: Breast cancer feed arteries are thin-walled and produce lower tension than control arteries of similar diameter in response to norepinephrine, thromboxane-analog U46619, endothelin-1, and depolarization with elevated [K+]. Fewer layers of similarly-sized vascular smooth muscle cells explain the reduced media thickness of breast cancer arteries. Evidenced by lower media stress, norepinephrine-induced and thromboxane-induced tension development of breast cancer arteries is reduced more than is explained by the thinner media. Conversely, media stress during stimulation with endothelin-1 and elevated [K+] is similar between breast cancer and control arteries. Correspondingly, vascular smooth muscle cell depolarizations and intracellular Ca2+ responses are attenuated in breast cancer feed arteries during norepinephrine but not during endothelin-1 stimulation. Protein expression of α1-adrenoceptors and messenger RNA levels for α1A-adrenoceptors are lower in breast cancer arteries than control arteries. Sympathetic vasocontraction elicited by electrical field stimulation is inhibited by α1-adrenoceptor blockade and reduced in breast cancer feed arteries compared to control arteries. CONCLUSION: Thinner media and lower α1-adrenoceptor expression weaken contractions of breast cancer feed arteries in response to sympathetic activity. We propose that abnormalities in breast cancer arteries can be exploited to modify tumor perfusion and thereby either starve cancer cells or facilitate drug and oxygen delivery during chemotherapy or radiotherapy.