Exercise training and atrial fibrillation: a systematic review and literature analysis

OBJECTIVE

There are concerns in maintaining adequate levels of physical activity in patients with atrial fibrillation (AF). This could be related to the type of exercise delivered, different among studies, as the words used to describe it as treatment. We have analysed the state-of-art of the role of the exercise in AF by a mathematical analysis. This analysis documented the connections between topics and updated the available evidence through a systematic review of the current literature.

MATERIALS AND METHODS

A literature search was conducted using specific terms for studies published between 2000 and 2019. For the descriptive analysis of the current literature, we used the LExical Network analysed by the Graph THeory (LENGTH) method, while to perform our review we followed the PRISMA statement. Downs and Black Quality Index was also used to assess the quality of studies. The LENGTH approach indicated nonspecific terms as "exercise", "physical" and "activity" as more representative than "rehabilitation" to describe the intervention.

RESULTS

The systematic review identified nine studies on 882 patients of moderate (n=4) to good (n=5) quality. Training consisted of a combination of supervised ambulatory and home-based outpatient programs, focused on aerobic elements (endurance and resistance training, walking, treadmill and bicycle ergometer). Significant improvements in 6-minute walking test distance and peak oxygen uptake and in quality of life were obtained, with high adherence to training and no serious/significant adverse events. Only one trial was based on cardiac rehabilitation principles.

CONCLUSIONS

Adequate exercise training can get a favourable cardiovascular outcome in patients with AF.

Duchenne muscular dystrophy: preliminary experience with sacubitril-valsartan in patients with asymptomatic left ventricular dysfunction

OBJECTIVE

Duchenne muscular dystrophy (DMD) is an inherited X-linked recessive neuromuscular disease caused by mutations of the dystrophin gene, leading to early and progressive muscle deterioration and dilated cardiomyopathy. The aim of this investigation was to assess whether treatment with sacubitril/valsartan (S/V) is well tolerated and may have beneficial effects in DMD patients with left ventricle (LV) dysfunction.

PATIENTS AND METHODS

We administered S/V to 3 DMD patients (19-29 yeard old) with LV ejection fraction <35% at echocardiography but no symptoms of heart failure. All patients were on optimal medical therapy. S/V was initiated at a very low dose of 12/13 mg/die, after withdrawal of angiotensin-converting enzyme inhibitor therapy, and slowly titrated to the dose of 49/51 mg twice daily or the maximally tolerated dose. Clinical and echocardiographic follow-up was performed after 3, 6 and 12 months.

RESULTS

At baseline, the LV ejection fraction was 32±1%. A significant improvement of LV ejection fraction was observed at 3 months (44.0±6.0%; p<0.05), which was maintained at 6 (45.7±5.0%) and 12 (43.3±3.2%) months (p<0.05 for both). No relevant side effects were reported throughout the period of the study.

CONCLUSIONS

Our preliminary data suggest that, in DMD patients with reduced LV ejection fraction, S/V is safe and may improve LV function.

Microvascular ischemia in patients with successful percutaneous coronary intervention: effects of ranolazine and isosorbide-5-mononitrate

OBJECTIVE

About one-third of patients undergoing percutaneous coronary interventions (PCIs) for flow-limiting coronary stenosis continue to develop signs of myocardial ischemia (MI) during exercise stress test [EST], despite successful coronary revascularization. Coronary microvascular dysfunction is a likely major cause of the persistence of EST-induced MI in these patients.

PATIENTS AND METHODS

We studied 15 patients (14 men, age 67±5 years) fulfilling the following strict inclusion criteria: (1) recent PCI (<6 months), with drug-eluting stent, of coronary artery stenoses for stable angina, with evidence of full success (no residual stenosis >20% in any vessel); (2) persistence of ST-segment depression induction during EST. After a basal investigation, patients received either ranolazine (375 mg bid) or isosorbide-5-mononitrate (ISMN, 20 mg bid) for 3 weeks in a single-blind, randomized crossover study. Clinical assessment, symptom-limited EST, echocardiographic color-Doppler, with tissue-Doppler examination, and coronary microvascular dilator response to adenosine (CFR-ADO) and cold pressor test (CFR-CPT), assessed by transthoracic echo-Doppler, were obtained at baseline and the end of the 3-week therapy with each drug.

RESULTS

Compared to both baseline and ISMN, ranolazine showed a longer time to 1 mm ST-segment depression (404±116 s vs. 317±98 and 322±70 s, respectively; p<0.01). No differences were observed in coronary microvascular function and diastolic left ventricular function between the 2 drugs and compared to baseline.

CONCLUSIONS

Our data show that ranolazine, but not ISMN, improved time to ischemia during EST. This effect, however, was independent of any effects on coronary microvascular and diastolic function.

Diagnostic role of echocardiography in patients admitted to the emergency room with suspect no-ST-segment elevation acute myocardial infarction

OBJECTIVE

We investigated whether echocardiography may help identify, among patients admitted with a suspect of non-ST-segment elevation acute myocardial infarction (NSTEMI), those with athero-thrombotic coronary artery disease (CAD).

PATIENTS AND METHODS

We studied consecutive patients admitted with a clinical suspect of first NSTEMI. Echocardiography was assessed within 24 hours from admission. Patients were divided into two groups, according to the results of coronary angiography: 1) patients with obstructive stenosis (≥ 50%) and/or images of thrombosis in one or more coronary arteries (CAD group); 2) patients with no evidence of obstructive coronary arteries (NOCAD group).

RESULTS

Of 101 patients enrolled in the study, 53 (52.5%) showed obstructive CAD and 48 (47.5%) NOCAD. At echocardiographic examination, regional wall motion abnormalities were found in 52.8% of patients in the CAD group and 43.7% in the NOCAD group (p=0.43). Left ventricle ejection fraction was 56.4±6.8 vs. 54.7±9.8% (p=0.30) and wall motion score index was 1.16±0.26 vs. 1.21±0.32 (p=0.39) in the two groups, respectively. A multivariable logistic regression independent predictors of obstructive CAD included age, male gender, typical angina, diabetes and hypertension.

CONCLUSIONS

Our data showed that, in patients with acute chest pain and increased serum troponin T concentration, routine standard echocardiography does not significantly improve the diagnostic accuracy for the presence of obstructive CAD.

Correlation between coronary microvascular function and angina status in patients with stable microvascular angina

BACKGROUND

Classical anti-ischemic drugs are the first-line form of treatment in patients with microvascular angina (MVA), but they often fail to achieve a satisfactory control of angina symptoms. It is unknown whether there is any relation between improvement of angina status and changes in microvascular function induced by classical anti-ischemic drugs in MVA patients.

AIM

To assess whether, in MVA patients, the effects of classical anti-ischemic drugs on symptoms and quality of life (QoL) are related to changes in coronary microvascular function.

PATIENTS AND METHODS

We studied 51 patients (59±10 years; 15 men) with MVA. Coronary blood flow (CBF) response to adenosine (ADO) and to cold pressor test (CPT), Seattle Angina Questionnaire (SAQ) and EuroQoL scale were assessed at baseline, in pharmacological washout, and after 12 months under anti-ischemic therapy. Patients were divided into 2 groups: (1) Group 1 included patients with no improvement of QoL (EuroQoL score change < 10 points); (2) Group 2 included patients with QoL improvement (increase in EuroQoL score ≥ 10 points).

RESULTS

At baseline, the 2 groups were similar in age, gender, cardiovascular risk factors, CBF response to ADO and to CPT, SAQ and EuroQoL scores. At follow-up the 2 groups differed only for beta blockers use (27% vs. 88% in group 1 and 2, respectively; p < 0.001). A significant improvement in SAQ score was observed only in group 2. CBF response to both ADO and CPT showed a similar improvement in the 2 groups. No relation was found between changes in coronary microvascular function and in angina status.

CONCLUSIONS

In MVA patients beta-blockers are more effective than other anti-ischemic drugs in improving angina symptoms. The improvement of angina status does not seem to be mediated by changes in coronary microvascular function.

Near-barrier fusion of the ⁸B + ⁵⁸Ni proton-halo system

Fusion cross sections were measured for the exotic proton-halo nucleus ⁸B incident on a ⁵⁸Ni target at several energies near the Coulomb barrier. This is the first experiment to report on the fusion of a proton-halo nucleus. The resulting excitation function shows a striking enhancement with respect to expectations for normal projectiles. Evidence is presented that the sum of the fusion and breakup yields saturates the total reaction cross section.

Measurement of nuclear transparency for the A(e,e'pi+) reaction

We have measured the nuclear transparency of the A(e,e'pi+) process in 2H, 12C, 27Al, 63Cu, and 197Au targets. These measurements were performed at the Jefferson Laboratory over a four momentum transfer squared range Q2=1.1 to 4.7 (GeV/c)2. The nuclear transparency was extracted as the super-ratio of (sigmaA/sigmaH) from data to a model of pion-electroproduction from nuclei without pi-N final-state interactions. The Q2 and atomic number dependence of the nuclear transparency both show deviations from traditional nuclear physics expectations and are consistent with calculations that include the quantum chromodynamical phenomenon of color transparency.

Onset of quark-hadron duality in pion electroproduction

A large data set of charged-pion (pi+/-) electroproduction from both hydrogen and deuterium targets has been obtained spanning the low-energy residual-mass region. These data conclusively show the onset of the quark-hadron duality phenomenon, as predicted for high-energy hadron electroproduction. We construct several ratios from these data to exhibit the relation of this phenomenon to the high-energy factorization ansatz of electron-quark scattering and subsequent quark-->pion production mechanisms.