Multi-modality imaging for pre-procedural planning of transcatheter mitral valve interventions.

Transcatheter mitral valve interventions (TMVI), either repair or replacement, are established alternative options for patients with mitral regurgitation (MR) deemed not suitable for conventional open-heart surgery. Multi-modality imaging plays a pivotal role in the selection of patients, gaining insights into the anatomy of the mitral valve the mechanism and the severity of MR, which are essential to predict the success of these procedures. The aim of this review is to provide an overview on the role of multi-modality imaging in the patient selection and pre-procedural planning of TMVI.

The value of the 12-lead electrocardiogram in the prediction of sudden cardiac death.

Sudden cardiac death (SCD) can be caused by several clinical conditions, overt or misconceived, which recognize different pathophysiologies determining the development of fatal arrhythmic events. In the various forms of structural heart disease such as ischaemic heart disease, cardiomyopathies (e.g. hypertrophic cardiomyopathy, dilated cardiomyopathy, and arrhythmogenic cardiomyopathy), channelopathies (e.g. long-QT syndrome, congenital short QT, Brugada syndrome, early repolarization (ER) syndrome, and idiopathic ventricular fibrillation) but also in the apparently healthy subject, the 12-lead electrocardiogram (ECG) has proved, over the years, to be a reliable and readily available method for stratifying the risk of adverse arrhythmic events and consequently SCD. Several electrocardiographic markers have been shown to be associated with adverse outcomes in different types of patients. Although with different sensitivity and specificity in each clinical condition, depolarization abnormalities, such as QRS fragmentation, Q waves, QRS duration, left posterior fascicular block, low QRS voltage, and left ventricular hypertrophy and similarly repolarization abnormalities as ER pattern, T wave alternans, QT interval, and QT dispersion, have shown significant efficacy in predicting SCD. Despite the advancement of techniques especially in the field of imaging, the correct interpretation of the 12-lead ECG remains, therefore, an effective tool for assessing the possible prognostic outcome in terms of arrhythmic risk and SCD in different types of patients.

Echocardiography in cardioembolic stroke prevention.

Stroke is a leading cause of mortality and disability, and cardiac embolism accounts for one-third of all ischaemic strokes. Thirty per cent of strokes are cryptogenic. In this setting, echocardiography is essential in the diagnosis, treatment, and prevention of embolic stroke of undetermined source since it is a widely available, safe, and inexpensive tool. Transthoracic echocardiography and transoesophageal echocardiography, furthermore, are proven to change therapeutic management leading to initiation of anti-coagulation, anti-microbial therapy, patent foramen ovale (PFO) closure, or cardiac tumour resection. The most common cardioembolic sources include left atrial appendage thrombus, left ventricular thrombus, vegetations in endocarditis, paradoxical embolization in PFO, prosthesis thrombosis, and intracardiac tumours. Although the presence of a cardioembolic source only represents a risk factor for an ischaemic stroke, it could not assure the certain or the unique cause of the event. The purpose of this review is to underline the importance of echocardiography and overview the main sources of cardiac embolism and the echocardiographic features.

Secondary prevention and follow-up of patients with ACS and not-at-target LDL: An Italian real-world retro-prospective analysis by the inertia group.

Background: In patients with recent ACS, the latest ESC/EAS guidelines for management of dyslipidaemia recommend intensification of LDL-C-lowering therapy. Objective: Report a real-world picture of lipid-lowering therapy prescribed and cholesterol targets achieved in post-ACS patients before and after a specific educational program. Methods: Retrospective data collection prior to the educational course and prospective data collection after the course of consecutive very high-risk patients with ACS admitted in 2020 in 13 Italian cardiology departments, and with a non-target LDL-C level at discharge. Results: Data from 336 patients were included, 229 in the retrospective phase and 107 in the post-course prospective phase. At discharge, statins were prescribed in 98.1% of patients, alone in 62.3% of patients (65% of which at high doses) and in combination with ezetimibe in 35.8% of cases (52% at high doses). A significant reduction was obtained in total and LDL cholesterol (LDL-C) from discharge to the first control visit. Thirty-five percent of patients achieved a target LDL-C <55 mg/dL according to ESC 2019 guidelines. Fifty percent of patients achieved the <55 mg/dL target for LDL-C after a mean of 120 days from the ACS event. Conclusions: Our analysis, though numerically and methodologically limited, suggests that management of cholesterolaemia and achievement of LDL-C targets are largely suboptimal and need significant improvement to comply with the lipid-lowering guidelines for very high CV risk patients. Earlier high intensity statin combination therapy should be encouraged in patients with high residual risk.

Long-term effects of bariatric surgery on peripheral endothelial function and coronary microvascular function.

BACKGROUND: We previously demonstrated that bariatric surgery (BS) leads to a short-term significant improvement of endothelial function and coronary microvascular function. In this study we assessed whether BS maintains its beneficial effect at long-term follow up. DESIGN: We studied 19 morbidly obese patients (age 43±9years, 12 women) without any evidence of cardiovascular disease who underwent BS. Patients were studied before BS, at 3 months and at 4.0±1.5years follow up. METHODS: Peripheral vascular function was assessed by flow-mediated dilation (FMD) and nitrate-mediated dilation (NMD), i.e., brachial artery diameter changes in response to post-ischemic forearm hyperhaemia and to nitroglycerin administration, respectively. Coronary microvascular function was assessed by measuring coronary blood flow (CBF) response to intravenous adenosine and to cold pressor test (CPT) in the left anterior descending coronary artery. RESULTS: Together with improvement of anthropometric and metabolic profile, at long-term follow-up patients showed a significant improvement of FMD (6.43±2.88 vs. 8.21±1.73%, p=0.018), and CBF response to both adenosine (1.73±0.48 vs. 2.58±0.54; p<0.01) and CPT (1.43±0.30 vs. 2.23±0.48; p<0.01), compared to basal values. No differences in vascular end-points were shown at 3-month and 4-year follow-up after BS. CONCLUSIONS: Our data show that, in morbidly obese patients, BS exerts beneficial and long lasting effects on peripheral endothelial function and on coronary microvascular dilator function.

Percutaneous management of failed bioprosthetic pulmonary valves in patients with congenital heart defects.

AIMS: We reviewed our center experience in the field of transcatheter pulmonary valve-in-valve implantation (TPViV), that is emerging as a treatment option for patients with pulmonary bioprosthetic valve (BPV) dysfunction. METHODS: Between April 2008 and September 2015, a total of six patients with congenital heart disease (four men) underwent TPViV due to stenosis of preexisting BPV. Four patients received a Melody Medtronic Transcatheter Pulmonary Valve and two an Edward Sapien Valve. RESULTS: No procedural-related complications occurred. After valve implantation, right ventricular systolic pressure (RVSP, 80.5 ±â€Š25.3-41.2 ±â€Š8.35 mmHg, P < 0.05), right ventricular outflow tract (RVOT) gradient (55.3 ±â€Š23.4-10.6 ±â€Š3.8 mmHg, P < 0.05), and RVSP-to-aortic pressure (0.75 ±â€Š0.21-0.38 ±â€Š0.21, P = 0.01) fell significantly. Echocardiograms at follow-up revealed a significant reduction in estimated RVSP (88.7 ±â€Š22-21.7 ±â€Š4.7 mmHg, P < 0.05), in RVOT (76.2 ±â€Š17.9-25.7 ±â€Š6.1 mmHg, P = 0.005), and in mean RVOT (40.7 ±â€Š9.9-15.5 ±â€Š4.8 mmHg, P < 0.05) gradients. Cardiac magnetic resonance showed no significant change in biventricular dimensions and function. Symptomatic patients reported improvement of symptoms, although cardiopulmonary exercise did not show any significant differences. CONCLUSION: TPViV is an effective and well tolerated treatment for BPV dysfunction, improving freedom from surgical reintervention. Long-term studies will redefine the management of dysfunctional RVOT, either native or surrogate.

Peripheral arterial function and coronary microvascular function in patients with variant angina.

OBJECTIVES: In this study, we assessed whether any abnormalities in coronary microvascular and peripheral vasodilator functions are present in patients with variant angina (VA) caused by epicardial coronary artery spasm (CAS). METHODS: We studied 23 patients with VA (i.e. angina at rest, ST-segment elevation during angina attacks and documented occlusive CAS at angiography) and 18 matched healthy controls. Endothelium-dependent and -independent coronary microvascular function was assessed by measuring coronary blood flow (CBF) response to adenosine and the cold pressor test (CPT) in the left anterior descending artery by transthoracic Doppler echocardiography. Systemic endothelium-dependent and -independent arterial dilator function was assessed by measuring brachial flow-mediated dilation (FMD) and nitrate-mediated dilation (NMD), respectively. RESULTS: In VA patients, CBF responses to both adenosine (1.71 ± 0.25 vs. 2.97 ± 0.80, p < 0.01) and CPT (1.68 ± 0.23 vs. 2.58 ± 0.60, p < 0.01) were reduced compared to controls. Brachial FMD was also lower (3.87 ± 2.06 vs. 8.51 ± 2.95%, p < 0.01), but NMD was higher (16.7 ± 1.8 vs. 11.9 ± 1.4%, p < 0.01) in patients compared to controls. Differences were independent of the presence of coronary atherosclerotic lesions at angiography. CONCLUSIONS: Our data show that patients with VA have a generalized vascular dysfunction that involves both peripheral artery vessels and coronary microcirculation.

Effects of ivabradine and ranolazine in patients with microvascular angina pectoris.

Patients with microvascular angina (MVA) often have persistence of symptoms despite full classical anti-ischemic therapy. In this study, we assessed the effect of ivabradine and ranolazine in MVA patients. We randomized 46 patients with stable MVA (effort angina, positive exercise stress test [EST], normal coronary angiography, coronary flow reserve <2.5), who had symptoms inadequately controlled by standard anti-ischemic therapy, to ivabradine (5 mg twice daily), ranolazine (375 mg twice daily), or placebo for 4 weeks. The Seattle Angina Questionnaire (SAQ), EuroQoL scale, and EST were assessed at baseline and after treatment. Coronary microvascular dilation in response to adenosine and to cold pressor test and peripheral endothelial function (by flow-mediated dilation) were also assessed. Both drugs improved SAQ items and EuroQoL scale compared with placebo (p <0.01 for all), with ranolazine showing some more significant effects compared with ivabradine, on some SAQ items and EuroQoL scale (p <0.05). Time to 1-mm ST-segment depression and EST duration were improved by ranolazine compared with placebo. No effects on coronary microvascular function and on flow-mediated dilation were observed with drugs or placebo. In conclusion, ranolazine and ivabradine may have a therapeutic role in MVA patients with inadequate control of symptoms in combination with usual anti-ischemic therapy.

Lack of effect of nitrates on exercise stress test results in patients with microvascular angina.

PURPOSE: To assess the effects of short-acting nitrates on exercise stress test (EST) results and the relation between EST results and coronary blood flow (CBF) response to nitrates in patients with microvascular angina (MVA). METHODS: We completed 2 symptom/sign limited ESTs on 2 separate days, in a random sequence and in pharmacological washout, in 29 MVA patients and in 24 patients with obstructive coronary artery disease (CAD): one EST was performed without any intervention (control EST, C-EST), and the other after sublingual isosorbide dinitrate, 5 mg (nitrate EST, N-EST). CBF response to nitroglycerin (25 µg) was assessed in the left anterior descending coronary artery by transthoracic Doppler-echocardiography. RESULTS: At C-EST. ST-segment depression ≥1 mm (STD) was induced in 26 (90 %) and 23 (96 %) MVA and CAD patients, respectively (p=0.42), whereas at N-EST, STD was induced in 25 (86 %) and 14 (56 %) MVA and CAD patients, respectively (p=0.01). Time and rate pressure product at 1 mm STD increased during N-EST, compared to C-EST, in CAD patients (475±115 vs. 365±146 s, p<0.001; and 23511±4352 vs. 20583±6234 bpm∙mmHg, respectively, p=0.01), but not in MVA patients (308±160 vs. 284±136 s; p=0.19; and 21290±5438 vs. 20818±4286 bpm∙mmHg, respectively, p=0.35). In MVA patients, a significant correlation was found between heart rate at STD during N-EST and CBF response to nitroglycerin (r=0.40, p=0.04). CONCLUSIONS: Short-acting nitrates improve EST results in CAD, but not in MVA patients. In MVA patients a lower nitrate-dependent coronary microvascular dilation may contribute to the lack of effects of nitrates on EST results.

Coronary microvascular dysfunction after elective percutaneous coronary intervention: correlation with exercise stress test results.

OBJECTIVES: We assessed whether exercise stress test (EST) results are related to the presence of coronary microvascular dysfunction (CMVD) in patients undergoing elective percutaneous coronary intervention (PCI). BACKGROUND: Previous studies showed that EST is poorly reliable in predicting restenosis after PCI; some studies also showed CMVD in the territory of the treated vessel. METHODS: We studied 29 patients (age 64 ± 6, 23 M) with stable coronary artery disease and isolated stenosis (>75%) of the left anterior descending (LAD) coronary artery, undergoing successful PCI with stent implantation. EST and assessment of coronary microvascular function were performed 24h, 3 months and 6 months after PCI. Coronary blood flow (CBF) response to adenosine and to cold-pressor test (CPT) was assessed in the LAD coronary artery by transthoracic Doppler echocardiography. RESULTS: Patients with ST-segment depression ≥ 1 mm at EST performed 24h after PCI (n=11, 38%) showed a lower CBF response to adenosine compared to those with negative EST (1.65 ± 0.4 vs. 2.11 ± 0.4, respectively, p=0.003), whereas the difference in CBF response to CPT was not significant (1.44 ± 0.4 vs. 1.64 ± 0.3, respectively; p=0.11). At 3-month and 6-month follow-up a positive EST was found in 12 (41%) and 13 (44%) patients, respectively; patients with positive EST also had lower CBF response to adenosine compared to those with negative EST (3 months: 1.69 ± 0.3 vs. 2.20 ± 0.3, respectively; 6 months: 1.66 ± 0.2 vs. 2.32 ± 0.3, respectively; p<0.001 for both). CONCLUSIONS: Positive EST after elective successful PCI consistently reflects impairment of hyperemic CBF due to CMVD, which persists over a follow-up period of 6 months.

Differential effects of heart rate reduction by atenolol or ivabradine on peripheral endothelial function in type 2 diabetic patients.

OBJECTIVE: To assess whether reduction of heart rate (HR) has beneficial effects on endothelial function in patients with type 2 diabetes mellitus (T2DM). DESIGN: Randomised, double-blind, placebo-controlled study. SETTING: University hospital. PATIENTS: 66 T2DM patients without overt cardiovascular disease. INTERVENTIONS: Patients were randomised to receive for 4 weeks, in addition to their standard therapy, one of the following treatments: atenolol (25 mg twice daily), ivabradine (5 mg twice daily) or placebo (1 tablet twice daily). MAIN OUTCOME MEASURES: Systemic endothelial function, assessed by flow-mediated dilation (FMD); endothelium-independent vasodilation, assessed by nitrate-mediated dilation (NMD); cardiac autonomic function, assessed by HR variability (HRV). RESULTS: 61 patients completed the study (19, 22 and 20 patients in atenolol, ivabradine and placebo groups, respectively). Compared with baseline, HR was similarly reduced by atenolol (87±13 vs 69±9 bpm) and ivabradine (86±12 to 71±9 bpm), but not by placebo (82±10 vs 81±9 bpm) (p<0.001). FMD improved at follow-up in the atenolol group (4.8±1.7 vs 6.4±1.9%), but not in the ivabradine group (5.2±2.5 vs 4.9±2.2%) and in the placebo group (4.8±1.5 vs 4.7±1.7%) (p<0.01). NMD did not change significantly in any group. HRV parameters did not change in the placebo group; they, instead, consistently increased in the atenolol, whereas a mild increase in SDNNi was only observed in the ivabradine group. A significant correlation was found in the atenolol group between HR and FMD changes (r=-0.48; p=0.04). CONCLUSIONS: Despite a comparable reduction in HR, atenolol, but not ivabradine, improved FMD in T2DM patients suggesting that changes in HR are by themselves unlikely to significantly improve endothelial function.

Coronary microvascular function and cortical pain processing in patients with silent positive exercise testing and normal coronary arteries.

ST-segment depression during exercise stress testing in asymptomatic subjects showing normal coronary arteries is considered a "false-positive" result. Coronary microvascular dysfunction, however, might be a possible cause of ST-segment depression in these cases. We assessed the coronary blood flow response to adenosine and to cold pressor test in the left anterior descending artery, using transthoracic Doppler echocardiography in 14 asymptomatic subjects with exercise-induced ST-segment depression and normal coronary arteries (group 1), 14 patients with microvascular angina (group 2), and 14 healthy subjects (group 3). Flow-mediated dilation was assessed in the brachial artery. Central pain processing was assessed using cortical laser evoked potentials during chest and right hand stimulation with 3 sequences of painful stimuli. The coronary blood flow response to adenosine was 1.8 ± 0.4, 1.9 ± 0.5, and 3.1 ± 0.9 in groups 1, 2, and 3, respectively (p <0.001). The corresponding coronary blood flow responses to the cold pressor test were 1.74 ± 0.4, 1.53 ± 0.3, and 2.3 ± 0.6 (p <0.001). The flow-mediated dilation was 5.5 ± 2.3%, 4.6 ± 2.4%, and 9.8 ± 1.2% in the 3 groups, respectively (p <0.001). The laser evoked potential N2/P2 wave amplitude decreased throughout the 3 sequences of stimulation in groups 1 and 3 but not in group 2 (chest, -19 ± 22%, +11 ± 42% and -36 ± 12%, p <0.001; right hand, -22 ± 25%, +12 ± 43% and -30 ± 20%, p = 0.009; in groups 1, 2, and 3). In conclusion, exercise stress test-induced ST-segment depression in asymptomatic subjects with normal coronary arteries cannot be considered as a simple false-positive result, because it can be related to coronary microvascular dysfunction. The different symptomatic state compared to patients with microvascular angina can, at least in part, be explained by differences in cortical processing of neural pain stimuli.

Effect of shift work on endothelial function in young cardiology trainees.

BACKGROUND: Long-term shift work (SW) is associated with an increase in cardiovascular disease (CVD). Previous studies have shown that prolonged SW is associated with endothelial dysfunction, suggesting that this abnormality may contribute to the SW-related increase in cardiovascular risk. The immediate effect of SW on endothelial function in healthy subjects, however, is unknown. DESIGN: We studied endothelial function and endothelium-independent function in 20 healthy specialty trainees in cardiology at our Institute, without any cardiovascular risk factor (27.3 ± 1.9 years, nine males), at two different times: (1) after a working night (WN), and (2) after a restful night (RN). The two test sessions were performed in a random sequence. METHODS: Endothelial function was assessed by measuring brachial artery dilation during post-ischaemic forearm hyperaemia (flow-mediated dilation, FMD). Endothelium-independent function in response to 25 µg of sublingual glyceryl trinitrate (nitrate-mediated dilation, NMD) was also assessed. RESULTS: FMD was 8.02 ± 1.4% and 8.56 ± 1.7% after WN and RN, respectively (p = 0.025), whereas NMD was 10.5 ± 2.1% and 10.4 ± 2.0% after WN and RN, respectively (p = 0.48). The difference in FMD between WN and RN was not influenced by the numbers of hours slept during WN (<4 vs >4 hours) and by the duration of involvement of specialty trainees in nocturnal work (<12 vs >12 months). CONCLUSIONS: Our study shows that in healthy medical residents, without any cardiovascular risk factor, FMD is slightly impaired after WN compared to RN. Disruption of physiological circadian neuro-humoral rhythm is likely to be responsible for this adverse vascular effect.

[Coronary microvascular dysfunction. An update]. / In tema di disfunzione del microcircolo coronarico.

Several studies in the last years have shown that a dysfunction of coronary microcirculation may be responsible for abnormalities in coronary blood flow and some clinical pictures. Coronary microvascular dysfunction, in absence of other coronary artery abnormalities, can cause anginal symptoms, resulting in a condition named microvascular angina (MVA). MVA can occur in a chronic form, predominantly related to effort (stable MVA), more frequently referred as cardiac syndrome X, or in an acute form, most frequently ensuing at rest, which simulates an acute coronary syndrome (unstable MVA). The main abnormalities characterizing these two forms of MVA consist of an impaired vasodilation and an increased vasoconstriction of small resistive coronary arteries, respectively. The mechanisms responsible for stable MVA are still unclear, but seem to include, together with the known traditional cardiovascular risk factors, an abnormally increased cardiac adrenergic activity. The prognosis of stable MVA is good, but some patients have progressive worsening of symptoms. Clinical outcome of patients with unstable MVA is substantially unknown, as there are no specific studies about this population. Treatment of stable MVA includes traditional anti-ischemic drugs as first step; in case of persisting symptoms several other drugs have been proposed, including xanthine derivatives, ACE-inhibitors, statins and, in women, estrogens. Severe forms of intense constriction (or spasm) of small coronary arteries may cause transmural myocardial ischemia, as the microvascular form of variant angina and the tako-tsubo syndrome.

Evidence of increased platelet reactivity in the first six months after acute ST segment elevation myocardial infarction.

INTRODUCTION: Platelets play a crucial role in the pathogenesis of acute coronary syndromes. Accordingly, previous studies showed increased platelet reactivity on admission in these patients. In this study we assessed platelet reactivity at short-medium term follow-up in patients with ST-segment elevation acute myocardial infarction (STEMI). MATERIALS AND METHODS: Fifty-nine patients (58 ± 11 years, 45 men), treated with primary angioplasty, were studied 1 month after STEMI. Thirty-five patients were retested at 6 months. Twenty matched patients with stable coronary artery disease served as controls. Platelet reactivity was assessed by flow cyometry at rest and at peak exercise, with and without adenosine diphosphate (ADP) stimulation, by measuring monocyte-platelet aggregates (MPAs) and glycoprotein IIb/IIIa (CD41) expression in the MPA gate, and CD41 and fibrinogen receptor (PAC-1) expression in the platelet gate. RESULTS: Compared to controls, basal MPAs and CD41 in the MPA gate were higher in STEMI patients both at 1 month (p = 0.001 and p = 0.002, respectively) and at 6 months (p = 0.03 and p = 0.01, respectively). Basal CD41 and PAC-1 expression was also higher in STEMI patients at the two assessments compared to controls (P<0.001 for both). Exercise induced a similar increase in platelet reactivity in patients and controls. ADP induced a higher increase in CD41 platelet expression in STEMI patients compared to controls both at 1 and 6 months (P < 0.001). CONCLUSION: Platelet reactivity is increased in the first 6 months after STEMI. The persistence of increased platelet reactivity in this time period may play a role in the early recurrence of coronary events after STEMI.

Relation between cardiovascular risk factors and coronary microvascular dysfunction in cardiac syndrome X.

BACKGROUND: The causes of coronary microvascular dysfunction (CMVD) in patients with cardiac syndrome X (CSX) are largely unknown. Common cardiovascular risk factors (CVRFs) and increased markers of inflammation have been associated with CMVD in some studies, but their role in determining CMVD in CSX patients remains poorly known. METHODS AND RESULTS: We studied 71 CSX patients (56 ± 9 years, 23 men) and 20 healthy volunteers (52 ± 7 years, nine men). Using transthoracic Doppler echocardiography, coronary microvascular vasodilator function was assessed in the left anterior descending coronary artery as the ratio of diastolic coronary blood flow (CBF) velocity at peak intravenous adenosine administration and during cold pressor test (CPT) to the respective basal CBF velocity values. Common CVRFs tended to be more frequent and C-reactive protein (CRP) levels were higher (P < 0.001) in CSX patients than in controls. Both CBF responses to adenosine (2.05 ± 0.6 vs. 2.92 ± 0.9, P < 0.001) and to CPT (1.71 ± 0.6 vs. 2.42 ± 0.7, P < 0.001) were lower in CSX patients than in controls. The differences between the two groups in CBF response to adenosine and in CBF response to CPT remained highly significant (P < 0.01 for both) after adjustment for all CVRFs, including serum CRP levels. CONCLUSION: In CSX patients, both endothelium-dependent and endothelium-independent CMVD cannot be reliably predicted by CVRFs (including serum CRP levels), alone or in combination.

Usefulness of impairment of cardiac adrenergic nerve function to predict outcome in patients with cardiac syndrome X.

Patients with cardiac syndrome X (CSX) have an excellent long-term prognosis, but a significant number show worsening angina over time. Previous studies have found a significant impairment of cardiac uptake of iodine-123-meta-iodobenzylguanidine (MIBG) on myocardial scintigraphy, indicating abnormal function of cardiac adrenergic nerve fibers. The aim of this study was to assess whether cardiac MIBG results can predict symptomatic outcome in patients with CSX. Cardiac MIBG scintigraphy was performed in 40 patients with CSX (mean age 58 ± 5 years, 14 men). Cardiac MIBG uptake was measured by the heart/mediastinum uptake ratio and a single photon-emission computed tomographic regional uptake score (higher values reflected lower uptake). Clinical findings, exercise stress test parameters, sestamibi stress myocardial scintigraphy, and C-reactive protein serum levels were also assessed. At an average follow-up of 79 months (range 36 to 144), no patient had died or developed acute myocardial infarction. Cardiac MIBG defect score was significantly lower in patients with worsening versus those without worsening of angina status (13 ± 7 vs 38 ± 28, p = 0.001), in those with versus those without hospital readmission because of recurrent chest pain (15 ± 9 vs 35 ± 29, p = 0.01), and in those who underwent versus those who did not undergo repeat coronary angiography (11 ± 7 vs 36 ± 27, p = 0.001). Significant correlations were found between quality of life (as assessed by the EuroQoL scale) and heart/mediastinum ratio (r = 0.48, p = 0.002) and cardiac MIBG uptake score (r = -0.69, p <0.001). No other clinical or laboratory variable showed a significant association with clinical end points. In conclusion, in patients with CSX, abnormal function of cardiac adrenergic nerve fibers, as assessed by an impairment of cardiac MIBG uptake, identifies those with worse symptomatic clinical outcomes.

Relationship between cardiac autonomic function and sustained ventricular tachyarrhythmias in patients with an implantable cardioverter defibrillators.

AIMS: Low left ventricular ejection fraction (LVEF) is the main indication of implantable cardioverter defibrillators (ICD) in patients with dilated cardiomyopathy (DCM) for the primary prevention of sudden cardiac death, but ICD therapy at follow-up occurs in a minority of patients. We investigated whether heart rate variability (HRV) may improve risk stratification in DCM patients. METHODS AND RESULTS: We studied 42 patients (age 67.3 ± 3.5; 37 males) who had undergone ICD implant for either idiopathic or ischaemic DCM (LVEF <40%) 34.6 ± 19.7 months prior to the study (range 6-84). Patients underwent 24 h electrocardiographic Holter monitoring, and HRV was assessed over 2 hours in the afternoon showing stable sinus rhythm. Left ventricular ejection fraction was measured by two-dimensional echocardiography. The serum levels of C-reactive protein and N-terminal pro-B-type natriuretic peptide (NT-proBNP) were also obtained. The primary endpoint was the occurrence of appropriate ICD shocks in the 6 months preceding the study. The occurrence of appropriate ICD discharge from ICD implant was considered as a secondary endpoint. In the last 6 months, appropriate ICD shocks had occurred in seven patients (17%). There were no differences between patients with and without ICD shocks in clinical variables, as well as in LVEF and in C-reactive protein and NT-proBNP serum levels. In contrast, most HRV parameters were significantly depressed in patients with, compared with those without, ICD shocks; the most significant difference was shown for the average of the standard deviations of RR intervals in all consecutive 5 min segments (n » 12) within the 2 h (26.7 ± 9 vs. 39.7 ± 14 ms; P = 0.02) in the time domain and for LF amplitude (8.4 ± 3 vs. 14.8 ± 7 ms; P = 0.02) in the frequency domain. Implantable cardioverter defibrillator discharge had occurred in 11 patients (26%) since ICD implant (average 35 months). No clinical or laboratory variable showed significant differences between patients with or without ICD discharge, except very low-frequency (VLF) amplitude (23.8 ± 7 vs. 30.8 ± 10.6 ms, respectively; P = 0.049). CONCLUSION: In ICD patients with reduced LVEF, several depressed HRV indices were significantly associated with appropriate ICD shocks in the previous 6 months, and VLF amplitude was the only variable significantly associated with ICD shocks recorded since ICD implant. These data suggest that full HRV analysis might be helpful for improving risk stratification for life-threatening ventricular arrhythmias and ICD indication in patients with DCM.

Exercise stress test results in patients with bare metal stents or drug-eluting stents: pathophysiological and clinical implications.

BACKGROUND: Drug-eluting stents (DES) have reduced restenosis following percutaneous coronary intervention (PCI), but they seem to be associated with increased coronary endothelial dysfunction compared to bare metal stents (BMS). No data are available about the prognostic value of exercise stress test (EST) in PCI patients in the DES era. METHODS AND RESULTS: The 160 patients with coronary artery disease (CAD) who underwent PCI with either BMS (n=86) or DES (n=74) were studied. EST was performed 1 month after PCI. DES patients had a higher rate of positive EST compared to BMS patients (49% vs 32%; P=0.03). At a median follow-up of 18 months DES showed a lower rate of target vessel revascularization (TVR) (hazard ratio (HR) 0.37, P=0.07), but a higher rate of acute myocardial infarction (AMI) (HR 3.33, P=0.08). At multivariate Cox-regression time to 1 mm ST and low-workload ischemia were independent predictors of AMI (HR 0.96, P=0.03; and HR 6.24, P=0.009, respectively), as well as of TVR (HR 0.96, P=0.007; and HR 6.43, P=0.001, respectively). CONCLUSIONS: DES implantation is associated with a higher rate of positive EST, compared to BMS, 1 month after PCI, likely due to a higher prevalence of endothelial dysfunction. EST seems to be helpful in predicting clinical outcome in patients with coronary stent implantation.