Nitrate-potentiated head-up tilt testing (HUT) has a low diagnostic yield in patients with likely vasovagal syncope.

BACKGROUND: Vasovagal syncope (VVS) is characterized by a wide spectrum of clinical presentations, but the relationship between clinical presentation and response to head-up tilt testing (HUT) has not yet been evaluated in detail. The aim of this study was to assess the relationship between the clinical presentation of VVS and HUT and clinical outcome at long-term follow-up. METHODS: Out of 671 consecutive subjects undergoing nitroglycerin-potentiated HUT for suspected VVS, 369 patients with normal electrocardiogram and no structural heart disease were included in our study. RESULTS: A history suggestive of typical or atypical VVS was obtained in 198 and 171 patients, respectively. The positivity rate of HUT was 65% and 36% in patients with established and likely VVS, respectively (P < 0.0001). In patients with established VVS, a time interval of ≤28 days between the last syncope and HUT was the only independent predictor of a positive test. In patients with likely VVS, no variable was predictive of a positive HUT. At a mean follow-up of 43 ± 27 months, the rate of adverse events (all-cause mortality, syncope recurrence, and major diagnostic and/or therapeutic procedures) was similar in patients of both groups, independent of HUT results. CONCLUSION: In patients with likely VVS, HUT has a low-diagnostic yield and may be inadequate to establish a reliable diagnosis. Similar long-term outcomes were observed in patients with positive or negative test results, suggesting that HUT is of limited value in the management of patients with suspected neurally mediated syncope.

[Epidemiology of Tako-tsubo cardiomyopathy: the Tuscany Registry for Tako-tsubo Cardiomyopathy ]. / Epidemiologia della sindrome di tako-tsubo nel mondo reale: dati del Registro Toscano della Miocardiopatia da stress tipo Tako-tsubo.

BACKGROUND: Tako-tsubo (stress) cardiomyopathy (TTC) is a recently described acute cardiac syndrome that mimics ST-segment elevation myocardial infarction. The TTC Tuscany Registry is an observational prospective multicenter registry established to define the prevalence, epidemiology and prognosis of TTC in the Tuscany area. METHODS: From January 1 to December 31, 2009, 105 consecutive patients hospitalized in the 14 Cardiology Units of the Tuscany Region with a diagnosis of TTC, were enrolled in the registry. TTC diagnosis was made using the Mayo Clinic modified criteria. Clinical, instrumental, laboratory and 6-month follow-up data were collected. Results. TTC represented 1.2% of all myocardial infarctions in the Tuscany Region during 2009, and it was diagnosed in 0.6% of the angiographic exams performed during the same year. The data collected showed that TTC affects mainly the female gender (91%) in the post-menopausal period (70 ± 11 years), though 5% of patients were ≤50 years old. An antecedent stressful event was frequently detected (74%). The main clinical presentation was chest pain (86%), associated with ST-segment elevation (59%). Mean left ventricular ejection fraction on admission was 40 ± 9%, and was associated with apical (37%), midapical (49%) or midventricular (5%) wall motion abnormalities. Left ventricular ejection fraction recovered to 51 ± 9% in 7 ± 9 days. Heart failure was the most common complication in the acute phase (14%), and 4 patients presented with cardiogenic shock. No patient died during the index hospitalization. At 6-month follow-up, no patient had TTC recurrence, 9 patients were rehospitalized (7 for noncardiac disease) and 2 patients died of noncardiac causes. CONCLUSIONS: Our data, which represent the largest prospective series of patients with a diagnosis of TTC, show that the prevalence of TTC in Tuscany is similar that described in other national and international studies. Moreover, the data highlight that TTC may occur also in male patients and in patients aged <50 years. The mid-term prognosis is good, but the risk of acute complications related to heart failure cannot be neglected.

Prognostic value of combined perfusion and function by stress technetium-99m sestamibi gated SPECT myocardial perfusion imaging in patients with suspected or known coronary artery disease.

The incremental prognostic value of combined regional wall motion and perfusion over perfusion alone by gated single-photon emission computed tomographic myocardial perfusion scintigraphy has not been evaluated. Of the 402 consecutive patients who underwent stress single-photon emission computed tomographic myocardial perfusion scintigraphy for suspected myocardial ischemia, we identified 333 patients (217 men, mean age 63 +/- 10 years; exercise in 249 and dipyridamole adminstered to 84). Visual scoring of perfusion images and regional wall motion used 20 segments and a scale of 0 to 4. Resting and poststress left ventricular ejection fraction was automatically generated. On follow-up (median 13 months), 30 hard cardiac events (17 cardiac deaths, 13 nonfatal acute myocardial infarctions) and 66 total cardiac events (including hard events, 26 with unstable angina, and 10 who underwent late revascularization) occurred. After adjustment for prescan information, the best independent predictors of hard events were summed stress score for wall motion (Wald's chi-square 8.3, p <0.004) and several vascular territories with ischemia by perfusion/function (Wald's chi-square 6.2, p <0.01). The strongest predictors of all cardiac events were the number of ischemias (Wald's chi-square 32.1, p <0.0001) and the number of ischemic vascular territories by perfusion (Wald's chi-square 13.1, p <0.0001). Addition of function data to the combined model of perfusion data yielded an incremental value of 26% for predicting hard events but not for all events. In conclusion, the assessment of combined perfusion/function provides incremental prognostic information for further hard events with perfusion data alone; perfusion data best predict all cardiac events.

Can the reversible regional wall motion abnormalities on stress gated Tc-99m sestamibi SPECT predict a future cardiac event?

BACKGROUND: Myocardial stunning has recently been demonstrated by use of stress gated technetium 99m sestamibi single photon emission computed tomography (SPECT) myocardial perfusion scintigraphy. However, its prognostic value is less well determined. The aim of this study was to investigate the prognostic value of reversible regional wall motion abnormalities (RWMAs). METHODS AND RESULTS: We studied 303 consecutive subjects with known or suspected coronary artery disease who underwent 2-day stress-rest gated Tc-99m sestamibi SPECT and were followed up for 19 +/- 16 months. Clinical and test-derived variables were evaluated to predict cardiac death, nonfatal myocardial infarction (MI), unstable angina, and early or late coronary revascularization. Reversible RWMAs were identified in 102 patients. On Cox analysis, the presence, site, degree, and extent of reversible RWMAs did not identify an adverse outcome, except in patients without prior MI. After adjustment for prescan data, the strongest predictors of hard events and all cardiac events were poststress RWMAs and the amount of ischemia. The addition of poststress RWMAs to the combined model of prescan and perfusion data yielded incremental prognostic value. CONCLUSION: Poststress RWMAs and ischemia by perfusion were the most powerful predictive parameters of cardiac events. However, myocardial stunning should always be considered, particularly in patients without prior MI and in the referral of patients for early revascularization.

Mitral effective regurgitant orifice area versus left ventricular ejection fraction as prognostic indicators in patients with dilated cardiomyopathy and heart failure.

BACKGROUND: This study aimed at investigating the relative powers of the quantitative evaluation of functional mitral regurgitation (FMR) and ejection fraction (EF) in predicting the clinical changes and prognosis of dilated cardiomyopathy (DCM) with severe systolic dysfunction. METHODS: A total of 81 patients with DCM, EF < 0.40 and at least mild FMR were prospectively evaluated during a mean follow-up of 24 +/- 7 months. Twenty cardiac deaths were recorded. At the time of enrolment all patients underwent echocardiographic evaluation of the effective regurgitant orifice area (ERO), EF, left atrial area, and tenting area. In 42/81 patients, the data obtained at enrolment were compared to those measured at a mean follow-up of 10 +/- 2 months. A multivariate analysis was performed to determine the best predictor of NYHA class and mortality. RESULTS: There was a correlation between the NYHA class and the ERO (chi2 = 26.1, p = 0.0001) but not with EF (chi2 = 4.3, p = 0.22) and at multivariate analysis, the ERO was found to be the main determinant of the NYHA class (r = 0.64, standard error 0.6, p = 0.0001). The NYHA class remained unchanged or improved in 28/42 (67%) and deteriorated in 14/42 (33%) patients. In the first group, the ERO increased from 22.3 +/- 10 to 30.2 +/- 16.4 mm2 (p = 0.05) and the tenting area from 5.8 +/- 1.8 to 6.8 +/- 1.8 cm2 (p = 0.001); in the second group, the ERO increased from 25.1 +/- 5.6 to 39.0 +/- 14.5 mm2 (p = 0.04) and the tenting area from 5.9 +/- 2.1 to 7.6 +/- 1.8 cm2 (p = 0.0001), in both groups without significant changes in EF. The mortality was 8.1% in patients with an ERO < 21 mm2, 30.3% in patients with an ERO of 21-30 mm2, and 50% in those with an ERO > 30 mm2. The EF was similar in the three subgroups. At Cox multivariate analysis the best predictors of mortality were the ERO (chi2 = 13.83, p = 0.0001), EF (chi2 = 5.48, p = 0.019), and left atrial area (chi2 = 4.52, p = 0.04). CONCLUSIONS: FMR in DCM well correlated with the clinical status of the patients and its worsening was suggestive of progression of the disease. The ERO was found to be the best predictor of the NYHA class and mortality.

[Quantitative evaluation of functional mitral insufficiency in dilated cardiomyopathy: morphological and functional correlations]. / Valutazione quantitativa dell'insufficienza mitralica funzionale nella cardiomiopatia dilatativa: correlazioni morfologiche e funzionali.

BACKGROUND: Angiography and echo-color Doppler imaging are routinely used for the semiquantitative grading of functional mitral regurgitation (MR) in dilated cardiomyopathy. However, in case of severe regurgitation the results obtained using these two methods are discrepant. We propose quantitative echocardiographic evaluation and the related morphological parameters of remodeling of the ventricular and mitral apparatuses for the estimate of severe regurgitation. METHODS: Fifty-two patients with dilated cardiomyopathy and functional MR (28 males, 24 females, ejection fraction < or = 40%) were evaluated by means of echocardiography for a total of 73 echocardiograms (basal and 21 at the sixth month). The echo measurements included the left ventricular end-diastolic and end-systolic volumes, ejection fraction, area jet/left atrial area, diastolic and systolic mitral annulus areas and fractional contraction (MAC, %), systolic tenting area (TA, cm2, area enclosed between the annular plane and mitral leaflets), systolic tethering length (TL, cm, papillary tips and intervalvular fibrosa distance); quantitative Doppler (using the mitral and aortic stroke volumes) and PISA methods were averaged to calculate the regurgitant volume (RV, ml/beat), regurgitant fraction (RF, %), and effective regurgitant orifice (ERO, mm2). RESULTS: The strongest correlation with ERO, RV and RF was obtained with systolic TA (beta = 0.40, 0.67 and 0.60; SE 1.68, 1.56 and 1.38; p = 0.01, p = 0.0001 and p = 0.0001, respectively) and MAC (beta = -0.33, -0.61 and -0.61; SE 0.31, 0.31 and 1.49; p = 0.03, p = 0.0001 and p = 0.0001, respectively). We did not find any correlation with ejection fraction (p = NS). The following values were found to be indicative of severe functional MR: ERO > or = 40 mm2, RV > or = 49 ml/beat, RF > or = 57%, MAC < or = 12.5%, TA > or = 7.7 cm2, and TL > or = 4.7 cm. CONCLUSIONS: We did not find any significant correlation between the quantitative functional MR echo parameters and systolic dysfunction. The major determinants of ERO, RV and RF were the loss of MAC and larger systolic TAs. These parameters are significantly proportional to the severity of functional MR as assessed by the semiquantitative criteria commonly adopted in the clinical practice. We propose the values of ERO, RV, RF, TA, MAC and TL as indicative of severe functional MR.