Update on percutaneous mitral valve therapy: clinical results and real life experience.

Mitral regurgitation (MR) is a common valvulopathy worldwide increasing in prevalence. Cardiac surgical intervention, preferable repair, is the standard of care, but a relevant number of patients with severe MR do not undergo surgery because of high peri-operative risk. Percutaneous mitral valve repair with the MitraClip System has evolved as a new tool for the treatment of severe MR. The procedure simulates the surgical edge-to-edge technique, developed by Alfieri in 1991, creating a double orifice valve by a permanent approximation of the two mitral valve leaflets. Several preclinical studies, registries and Food and Drug Administration approved clinical trials (EVEREST, ACCESS-EU) are currently available. The percutaneous approach has been recently studied in a randomized controlled trial, concluding that the device is less effective at reducing MR, when compared with surgery, by associated with a lower adverse event rate. The patients enrolled in this trial had a normal surgical risk and mainly degenerative MR with preserved left ventricular function. On the other hand, results derived from the clinical "real life" experience, show that patients actually treated in Europe present a higher surgical risk profile, more complex mitral valve anatomy and functional MR in the most of cases. Thus these data suggest that MitraClip procedure is feasible and safe in this subgroup of patients that should be excluded from the EVEREST trial due to rigid exclusion criteria. Despite the promising results clinical experience is still small, and no data related the durability are currently available. Therefore, MitraClip device should be reserved now to high risk or inoperable patients.

Reduction of mitral valve regurgitation with Mitraclip® percutaneous system.

Mitral regurgitation (MR) is the second most common heart valve disease worldwide and the current gold-standard treatment is surgical repair or replacement. Nevertheless, many patients do not undergo surgical intervention due to several comorbidities. Percutaneous "edge-to-edge" mitral valve repair using the MitraClip System is an emerging and effective option to this subset of patients. This device has been used to treat both functional and degenerative mitral valve regurgitation and has been compared to surgery in the Endovascular Valve Edge-to-Edge Repair Study II (EVEREST II) randomized trial. Although the field of percutaneous management of MR is at an early stage, it has been demonstrated that percutaneous approaches can reduce MR, suggesting there is a great deal of potential for clinical benefit to patients with MR.

Contrast transesophageal echocardiography using the Acunav ultrasound catheter through the mouth way as a guide to percutaneous closure of patent foramen ovale.

AIM: Contrast-enhanced transesophageal echo-cardiography (c-TEE) represents the gold standard in the diagnosis of patent foramen ovale (PFO) but it is not always well tolerated by the patient, and it is influenced by his cooperation. Purpose of the present study was to assess feasibility and safety of c-TEE through the oral way using a miniaturized 10-Fr, monoplane probe (Acunav-TEE) and establish its utility in the diagnosis or PFO when compared with c-TEE using the traditional multiplane probe (standard-TEE). METHODS: From January 2008 to September 2008, 54 consecutive patients with presumed paradoxical cerebrovascular events and a suspected PFO were prospectively enrolled in this study. After signing a consensus form, these patients underwent both standard-TEE and Acunav-TEE in the same day by two independent operators. RESULTS: Feasibility of standard-TEE in our study was 96.3% (52/54) while feasibility of Acunav-TEE was 100% (54/54). When compared to standard-TEE, Acunav-TEE required shorter average time to insert the probe (1.0+/-0.2 vs. 4.1+/-1.1 minutes, P<0.001) but longer average time to look for the best projection and start the examination (13.8+/-2.4 vs. 9.1+/-2.7 minutes, P<0.001). Using standard-TEE as gold standard we defined a sensitivity of 100% (20/20) and a specificity of 97% (31/32) for Acunav-TEE. The positive predictive value, the negative predictive value and the global diagnostic accuracy were 95% (20/21), 100% (31/31) and 98% (51/52), respectively. CONCLUSION: Consistent with our experience, Acunav-TEE seems to be a feasible and safe technique when used for the diagnosis of PFO, with excellent sensitivity and specificity as compared with standard-TEE.

Long-term follow-up of percutaneous balloon valvuloplasty on stenotic mitral bioprosthesis.

Percutaneous balloon mitral valvuloplasty (PBMV) in patients with positive valve morphology has been recognized as an effective alternative to surgical treatment of mitral stenosis. In selected cases, PBMV has been used also in the treatment of bioprosthetic (Bp) valve dysfunction. We report one case of PBMV of a Bp: in this patient the advantage of such procedure has been the possibility to defer of some years the unavoidable substitution of the Bp, thus making also possible a new and complete surgical treatment for coronary artery disease.

[Dynamic obstruction to left ventricular outflow during dobutamine stress echocardiography: the probable mechanisms and clinical implications]. / Ostruzione dinamica all'efflusso ventricolare sinistro durante ecocardiografia da stress con dobutamina: probabili meccanismi ed implicazioni cliniche.

We observed the development of left ventricular outflow tract dynamic obstruction in some patients during dobutamine stress echocardiography. The purpose of this study was to identify the possible mechanisms and to consider the clinical implications. From 11/04/94 to 01/09/97 we studied 547 patients; 42 patients developed dynamic obstruction, defined as a late peak Doppler velocity profile that exceeded baseline outflow velocity by at least 1 m/s. The encountered mechanisms were: increased myocardial contractility; systolic anterior motion of the mitral valve; decreased venous return to the left ventricle, and peculiar characteristics of the left ventricular geometry. The results of this study show that the dynamic obstruction is mainly due to the first mechanism and secondarily to some characteristics of the left ventricular geometry. The hypotension observed in a few cases is not related to the dynamic obstruction but to beta 2 receptor hypersensibility to dobutamine. The symptoms, like dyspnea and chest pain, experienced by these patients are related to the dynamic obstruction rather than to the presence of coronary artery disease. In conclusion, we think that patients who develop dynamic obstruction, without wall motion abnormalities, during dobutamine stress echocardiography, may behave pathophysiologically as patients with obstructive hypertrophic cardiomyopathy, in whom diastolic dysfunction and outflow tract obstruction are responsible for symptoms. Therefore, these patients require a pharmacological treatment with beta blockers and/or non-dihydropyridine calcium channel blockers.

[Stress echocardiography with dobutamine in the identification of coronary disease in patients with left bundle branch block]. / Ruolo dell'eco-stress con dobutamina nell'identificazione di malattia coronarica in pazienti con blocco di branca sinistra.

Left bundle branch block does not permit an easy diagnosis of coronary heart disease (CAD) with provocative non-invasive test such as bicycle or treadmill stress test. Echocardiography allows the identification of segmental wall motion by evaluating the movement as well the thickness of the segment examined. Due to its agonist action on beta 1 receptors, dobutamine causes an increase in myocardial oxygen consumption and, as a consequence, may reveal myocardial ischemia; on this basis, we evaluated the sensibility, specificity and diagnostic accuracy of dobutamine stress-echo in identifying CAD in patients with left bundle branch block, and compared results with those obtained from coronary catheterization. From February 1994 to September 1995 we observed 25 patients with left bundle branch block (17 men, 8 women, mean age 61.8 +/- 8.4 years, range 43.75), affected or suspected for CAD. All patients underwent dobutamine stress-echo test and coronary arteriography. We divided patients into two groups: the first one (11 patients) with acute myocardial infarction, the second one (14 patients) without previous ischemic episodes. Diagnostic accuracy, specificity and sensibility of the stress-echo test were evaluated in order to identify significant stenosis of the left anterior descending (LAD), right coronary (RCA), and/or circumflex artery (CA). Dobutamine stress echocardiography showed in all patients, from basal to peak, an increase in blood pressure (from 121.2 +/- 17.4 to 141.8 +/- 23.6 mmHg), heart rate (from 81.3 +/- 10.9 to 140.7 +/- 8.9 b/min), and double product (from 9861.1 +/- 1898.1 to 19976.6 +/- 3603.6). In 8 (32%) patients who had typical chest pain, 7 had CAD. In 17 (68%) patients without chest pain, 5 had CAD and 12 had normal coronary arteries. Dobutamine stress echocardiography showed segmental wall motion variations only in 13 patients; 12 of them had a significant stenosis of coronary artery relative to the ischemic area, the other 1 was a false positive. Coronary arteriography showed stenosis of LAD in 10 and of RCA and/or CA in 12 patients, in both groups dobutamine stress-echo test had 1 false negative. Dobutamine stress echocardiography showed high diagnostic value as a provocative non-invasive test for CAD in patients with left bundle branch block. In conclusion, or study shows that no statistical difference exists in identifying ischemia in identifying ischemia in the LAD territory compared to RCA and/or CA. Further investigations are need to confirm the higher diagnostic accuracy in patients with left bundle branch block and to establish whether lower specificity in patients with a previous myocardial infarction is due to the smaller number of patients or to methodology.

[Significance of hypotension and vasovagal reflex during echo-stress using high doses of dobutamine]. / Significato dell'ipotensione e del riflesso vaso-vagale durante eco-stress con alte dosi di dobutamina.

Coronary artery disease (CAD) is one of the main causes of cardiovascular morbility and mortality. Actual research lines are directed towards the discovery of silent CAD before hard events as myocardial infarction and sudden death. Dobutamine stress echocardiography is an useful method to assess patients with suspected CAD who, are not able to stand an effort because of physical reasons. During the test, hypotension and/or bradycardia may occur and may cause interruption of the test. The aim of our study was to consider prevalence, meaning and clinical implications of hypotensive, sometimes associated to bradycardia, during dobutamine stress echocardiography. From April 1994 to June 1996, 363 consecutive patients (267 men and 96 women with an average age of 59.3 +/- 10 year) were examined because of suspected or known ischemic cardiopathy. All patients underwent dobutamine stress echocardiography and coronary arteriography. Neither hypotension nor bradycardia was noted in 285 of our patients (78.51%), while in the remaining 78 patients (21.48%) there was a pressure drop > or = 20 mmHg; bradycardia appeared in 6 patients. The study shows that it does not exist a statistically significant difference between the percentage of the patients with CAD of the control group and those of the hypotensive group (91.9 vs 83.3%, NS). As for the changes in well motion score index, there was not a statistically significant difference between patients improved score index in the control group and in the hypotensive group (80 vs 74.3%, NS). The 6 patients with hypotension and bradycardia had normal coronary arteries. In the light of these results hypotension, alone or associated with bradycardia, should not be considered as a negative prognostic factor and should not induce to the interruption of the dobutamine stress echocardiography.