598 PREVALANCE AND PREDICTORS OF LONG-TERM CARDIAC SYMPTOMS IN PATIENTS WITH TAKOTSUBO SYNDROME

Background

Takotsubo syndrome (TTS) is characterized by an acute and transient left ventricular dysfunction, usually involving the apical and midventricular segments, associated with troponin elevation and often triggered by either emotional or physical stressors. Once considered a benign condition, it is now clear that TTS patients have increased long-term mortality compared with the general population. Prevalence and the determinants of long-term cardiac symptoms in TTS patients have been scarcely investigated.

Methods

We enrolled consecutive patients admitted to our Centre with a diagnosis of TTS . All patients underwent invasive coronary angiography with left ventriculography at admission and only those fulfilling both the Mayo Clinic and Heart Failure Association criteria for a TTS diagnosis were selected for this study. Clinical, biochemical, and instrumental data were collected at admission and before discharge, and patients were followed-up for: symptoms recurrence (i.e., presence of effort angina and/or dyspnoea in the absence of other obvious causes) and all-cause mortality. The prevalence of long-term symptoms was further compared with a control group of unselected patients admitted for acute coronary syndromes (ACS) in the same period, matched for sex, age, and left ventricular ejection fraction (LVEF) at discharge.

Results

We eventually enrolled 118 patients (aged 73±10 years, 91% of whom were female). Acute chest pain was the most common presenting symptom (73%), followed by dyspnoea (32%), acute heart failure (16%), cardiogenic shock (9%), and syncope (8%). Most of cases (82%) were classified as having a typical (apical) LV dysfunction. Either a physical or an emotional stressor was identified in 37 (31%) and 31 (26%) of the patients, respectively. At admission, patients showed moderate systolic dysfunction (LVEF 40±9%), which was often improved at discharge (LVEF 52±8%). Over a median follow-up of 21 (interquartile interval 11-53) months, 35% of patients complained of some cardiac symptom: 32% of patients complained of effort dyspnoea and 7% (partially overlapping with the former) complained of effort angina. When compared with ACS patients (n=55, aged 71±10 years, 94% women, LVEF 53±9%), TTS patients featured a similar mortality rate, a lower (non-significant) prevalence of angina, and a significantly higher prevalence of dyspnoea (p=0.02). Notably, while a lower age at presentation (p=0.017) and a physical trigger (p=0.015) were significantly associated with the risk of recurrent angina, the absence of chest pain (p=0.044), a lower LVEF at admission (p=0.019), and a higher troponin T concentration at discharge (p=0.018) were associated with the presence of dyspnoea at follow-up. Finally, older age, male sex, renal dysfunction, cardiogenic shock, and concomitant coronary artery disease were all associated with a higher risk of death. Prescription of ACE-inhibitors and/or beta-blockers were associated with reduced risk (p<0.05, for all), in line with previous reports.

Conclusion

TTS is associated with a high risk of recurrent cardiac symptoms, mostly dyspnoea, over time. Selected clinical, biochemical, and instrumental characteristics may help identify patients more at risk, who may deserve a closer follow-up and potentially tailored therapies, to be investigated in future studies.

Increased density of M1 receptors in the hippocampus of juvenile rats chronically deprived of NGF

Binding studies were used to assess the changes in affinity and/or number of M1 muscarinic receptors in hippocampi from juvenile rats chronically deprived of NGF. NGF deprivation was obtained by implanting into right ventricle at postnatal day 2 (P2) hybrydoma cells secreting high levels of monoclonal antibodies against NGF (alphaD11). Parenteral myeloma cells (P3U) were used as controls. Competition experiments were used to characterise the [3H]-PNZ binding sites in membrane preparations of hippocampi from rats sacrificed at P15. [3H]-PNZ bound M1 receptors both in P3U and alphaD11 group as shown by displacing potency order of antagonists: TLZ=4-DAMP>PNZ>p-F-HHSiD>MTC. The deprivation of NGF for two weeks significantly increased the number of M1 receptors without changing the Ki values of antagonists with exception of methoctramine which showed an increase in affinity in alphaD11 group. Similar changes in binding parameters were already observed after the first week of anti-NGF treatment. In contrast, a treatment for a week with implant at postnatal day 15 failed to produce any changes in M1 binding parameters. These results provide further physiological evidence for developmentally regulated modulatory role of NGF in the cholinergic function in the hippocampus.