The Efficacy and Safety of Antegrade Inoue-Balloon Aortic Valvuloplasty to Treat Calcific Critical Aortic Stenosis.

BACKGROUND: Critical aortic stenosis (AS) with severe calcific degeneration often resists conventional retrograde percutaneous balloon aortic valvuloplasty (PBAV). To enhance therapeutic efficacy, a novel PBAV technique has been developed by utilizing a single Inoue balloon via an antegrade approach, performing multiple inflations with step-up increases (M-PBAV) of balloon diameter to the size of the surgical valve ring. PATIENTS AND METHODS: A total of 405 non-surgical patients with critical AS were treated by M-PBAV and the acute therapeutic response and long-term clinical course were evaluated; some patients underwent the procedure on two or three occasions. RESULTS: In a total of 456 procedures, mean transaortic valve pressure gradient improved from an initial 63.6 ± 17.3 mm Hg to 22.7 ± 8.9 mm Hg post PBAV (P<.01). Mean aortic valve area increased from an initial 0.55 ± 0.15 cm² to 0.98 ± 0.20 cm² immediately after M-PBAV (P<.01). Clinical symptoms (New York Heart Association [NYHA] class) improved over time. Prior to M-PBAV, baseline NYHA class I-II was 9.1%, and NYHA class III-IV was 90.9%. At 12 months post M-PBAV, mortality was 17.1%, with repeat M-PBAV plus surgical AVR at 12.7%, 10.5% NYHA class III-IV, and 59.6% NYHA class I-II. At 24 months post M-PBAV, mortality was 25.8%, with repeat PBAV plus surgical AVR at 19.0%, 8.8% NYHA class III-IV, and 46.2% NYHA class I-II. Adverse events related to the procedure included critical AR (0.5%), cardiac tamponade (1.8%), intraprocedure hemodynamic compromise requiring percutaneous cardiopulmonary support (0.5%), and reversible cerebral ischemia (1.3%). No myocardial infarct or vascular complications occurred. CONCLUSION: M-PBAV enhanced the therapeutic efficacy and procedural safety of valvuloplasty to treat severely calcified critical AS, and diversified its clinical roles.

Nifekalant hydrochloride administration during cardiopulmonary resuscitation improves the transmural dispersion of myocardial repolarization: experimental study in a canine model of cardiopulmonary arrest.

BACKGROUND: Because nifekalant hydrochloride (NIF) displayed a superior defibrillating effect on ventricular tachycardia/fibrillation (VT/VF) in cardiopulmonary arrest (CPA) patients, despite some QT prolongation, its effect on transmural dispersion of repolarization (TDR) in the left ventricle (LV) in an animal model of CPA was investigated. METHODS AND RESULTS: Eight beagle dogs were created with a myocardial infarction under anesthesia, and then VT/VF induction by continuous stimulation and cardiopulmonary resuscitation (CPR) were repeated. NIF (0.3 mg/kg) was administered under acidotic conditions (pH 7.26). The QTc interval measured by Y-lead ECG showed no significant prolongation before and after NIF. The activation recovery interval (ARI) measured by 64-lead LV surface mapping showed minimum ARI prolongation (40%) by NIF without maximum ARI prolongation, and as a result the ARI dispersion decreased by 67%. The repolarization time (RPT) with the plunge electrode showed 13-19% prolongation in the subendocardium and subepicardium with CPR, but NIF prolonged the RPT in the middle layer alone (17%), and as a result Plunge-TDR decreased by 82% (n=8, p<0.05). CONCLUSIONS: Administration of NIF during CPR decreased the TDR by RPT prolongation selectively in the middle layer. Because the subendocardial and subepicardial RPTs after CPR were already prolonged before NIF administration, it may have been the reason why the QT-prolonging effect of NIF was not reflected in the body surface ECG.

Can nifekalant hydrochloride be used as a first-line drug for cardiopulmonary arrest (CPA)? : comparative study of out-of-hospital CPA with acidosis and in-hospital CPA without acidosis.

BACKGROUND: Early defibrillation of ventricular tachycardia and fibrillation (VT/VF) is an urgent and most important method of resuscitation for survival in cardiopulmonary arrest (CPA). We have previously reported that nifekalant (NIF), a specific I(Kr) blocker developed in Japan, is effective for lidocaine (LID) resistant VT/VF in out-of-hospital CPA (OHCPA). However, little is known about the differences in the effect of NIF on OHCPA with acidosis and in-hospital CPA (IHCPA) without acidosis. METHODS AND RESULTS: The present study enrolled 91 cases of DC shock resistant VT/VF among 892 cases of CPA that occurred between June 2000 and May 2003. NIF was used (0.15-0.3 mg/kg) after LID according to the cardiopulmonary resuscitation (CPR) algorithm of Tokai University. The defibrillation rate was higher in the NIF group for both OHCPA and IHCPA than for LID alone, and the VT/VF rate reduction effect could be maintained even with acidosis. However, sinus bradycardia in OHCPA, and torsades de pointes in IHCPA were occasionally observed. These differences in adverse effects might be related to the amount of epinephrine, serum potassium levels, serum pH, and interaction with LID. CONCLUSIONS: NIF had a favorable defibrillating effect in both CPA groups, and it shows promise of becoming a first-line drug for CPR.

Effectiveness of short-term treatment with nocturnal oxygen therapy for central sleep apnea in patients with congestive heart failure.

OBJECTIVES: To evaluate the short term effects of inhalation of oxygen at night in 51 patients with congestive heart failure (CHF) and sleep apnea syndrome (SAS). METHODS: Fifty-one patients with stable CHF (31 males, 20 females, mean age 79.0 +/- 11.9 years; brain natriuretic peptide level of > 100 pg/ml) were evaluated between September 2003 and August 2004, using a Morpheus monitor. The complication rate of SAS in patients with CHF was assessed and apnea hypopnea index, oxygen desaturation index 3%, heart rate, and autonomic nerve activity under room air compared to supplemental O2 (2 l/min) over two consecutive nights. RESULTS: Thirty-eight (75%)of the CHF patients had SAS. Of these SAS patients, 49% suffered from central SAS and 51% had obstructive SAS. Apnea hypopnea index and oxygen desaturation index 3% improved remarkably with supplemental oxygen (p < 0.001), in particular, the central SAS group demonstrated prominent improvement (p < 0.001). Obstructive SAS patients exhibited no significant changes (p = 0.3356), but tended to exacerbate the episodes of sleep apnea. Total heart rate was decreased (p = 0.0079). Nevertheless, heart rate variability analysis showed little effect of nocturnal oxygen therapy on the autonomic nervous system during sleeping. CONCLUSIONS: Nocturnal oxygen therapy improved the number of sleep apnea episodes and decreased total heart rate during sleep time for the CHF patients with central SAS, despite little influence on the autonomic nervous system, based upon assessment of heart rate variability. Obstructive SAS might exacerbate the episodes of sleep apnea.