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Introduction: There are no studies on the long-term prognostic role of abnormal thyrotropin value in patients with acute cardiac diseases. Aim of the study was to assess the incidence and persistence of risk of cardiac and overall deaths in patients with acute cardiac diseases., Methods: A total of 1026 patients (mean age: 67.7 years) were divided into 4 groups: (1) euthyroid (EU, n=579); (2) subclinical-like hypothyroidism (SLHYPO, n=68); (3) subclinical-like hyperthyroidism (SLHYPER, n=23) and (4) low-triiodothyronine syndrome (LowT3, n=356). Follow-up started from the day of thyroid hormone evaluation (mean follow-up: 30 months). The events considered were cardiac and overall deaths., Results: Survival rate for cardiac death was lower in SLHYPO and in LT3 than in EU (log rank test; χ(2)=33.6; P < 0.001). Survival rate for overall death was lower in SLHYPO, SLHYPER and LowT3 than in EU (48.3; P < 0.001). After adjustment for several risk factors, the hazard ratio for cardiac death was higher in SLHYPO (3.65; P=0.004) in LowT3 (1.88; P=0.032) and in SLHYPER (4.73; P=0.047). Hazard ratio for overall death was higher in SLHYPO (2.30; P=0.009), in LowT3 (1.63; P=0.017) and in SLHYPER than in EU (3.71; P=0.004). Hazards for SLHYPO, SLHYPER and LowT3 with respect to EU were proportional over the follow-up period., Conclusion: In patients with acute cardiac disease, a mildly altered thyroid status was associated with increased risk of mortality that remains constant during all the follow-up.

Aims: A lower heart rate response (HRR) during vasodilator MPI has been shown to have a relevant adverse prognostic impact. We sought to evaluate the interaction among individual HRR to vasodilator stress and myocardial perfusion imaging (MPI) accuracy in patients with suspected ischemic heart disease (IHD). Methods and results: One hundred and sixty-five consecutive patients were submitted to vasodilator-stress MPI on a cardiac camera equipped with cadmium-zinc-thelluride detectors and coronary angiography. A coronary stenosis >70 % was considered significant. In every patient, the summed difference score (SDS) was computed from MPI images. Patients were categorized according to the tertiles of the distribution of individual HRR during dipyridamole: 'Group 1' (HRR < 8 bpm; lowest tertile); 'Group 2' (8 ≤ HRR ≤ 12 bpm; middle tertile); 'Group 3' (HRR >12 bpm; highest tertile). Significant coronary artery disease (CAD) was present in 102 (62 %) patients. In the overall population, MPI showed a significant accuracy (AUC: 0.81, 95 % CI 0.74-0.86; p < 0.001) in unmasking the presence of significant coronary stenosis. Interestingly, in patients with a blunted HRR during dipyridamole ('Group 1') MPI showed a significantly lower sensitivity (68 %) in detecting CAD than in those with a higher HRR ('Group 3') (91 %, p = 0.007), despite a preserved specificity (76 % vs 77 %, P=NS). Similarly, the correlation among CAD extent and post-stress LV functional stunning was limited to 'Group 3' patients, while it disappeared in those with blunted HRR. Conclusions: In patients with suspected IHD, MPI sensitivity is strongly influenced by the magnitude of patient heart rate increase to the pharmacologic stressor, suggesting an interaction among blunted HRR and lower accuracy in unmasking CAD. [ABSTRACT FROM AUTHOR]

The thyroid and the cardiovascular system are closely related, both in physiological and pathological conditions. The adverse consequences on the heart of overt thyroid disease are well-known and even subclinical forms of both hyperthyroidism and hypothyroidism are associated with increased cardiovascular mortality. In recent years, attention has shifted towards milder forms of thyroid disease, such as the so-called "low T3 syndrome", which is characterized by an isolated reduction in circulating levels of the biologically active form of thyroid hormone, triiodothyronine (T3). Furthermore, variations of T3 within the physiological range have been linked to coronary artery disease, one of the leading causes of morbidity and mortality worldwide. The present manuscript provides an overview of thyroid physiology and pathophysiology, with a particular focus on cardiovascular disease in patients with milder forms of thyroid dysfunction. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented in response to the article "Dronedarone: An emerging agent with rhythm- and rate-controlling effects," by Wegener F.T. and colleagues in the September 2006 supplement.