Type 2 diabetes mellitus is associated with faster degeneration of bioprosthetic valve: results from a propensity score-matched Italian multicenter study.

BACKGROUND: The present study was aimed at determining the impact of type 2 diabetes mellitus (DM) on postoperative bioprosthetic structural valve degeneration. METHODS AND RESULTS: Twelve Italian centers participated in the study. Patient data refer to bioprosthetic implantations performed from November 1988 to December 2009, which resulted in 6184 patients (mean age 71.3±5.4 years, 60.1% male) being enrolled. Of these patients, 1731 (27.9%) had type 2 DM. The propensity score-matching algorithm successfully matched 1113 patients with type 2 DM with the same number of no-DM patients. The postmatching standard differences were less than 0.1 for each of the covariates, and 64.2% of DM patients were matched. The early (30 days) mortality rate was 7.8% (n=87) versus 2.9% (n=33) in patients with or without type 2 DM (P<0.001), respectively. Seven-year freedom from valve deterioration was significantly lower in patients with DM (73.2% [95% confidence interval, 61.6-85.5] versus 95.4% [95% confidence interval, 83.9-100], P<0.001). In Cox regression models with robust SEs that accounted for the clustering of matched pairs, DM was the strongest predictor of structural valve degeneration (hazard ratio 2.39 [95% confidence interval 2.28-3.52]). When we allowed for interaction between type 2 DM and other key risk factors, DM remained a significant predictor beyond any potentially associated variable. CONCLUSIONS: Patients with type 2 DM undergoing bioprosthetic valve implantation are at high risk of early and long-term mortality, as well as of structural valve degeneration.

Assessment of a continuous blood gas monitoring system in animals during circulatory stress.

BACKGROUND: The study was aimed to determine the measurement accuracy of The CDI™ blood parameter monitoring system 500 (Terumo Cardiovascular Systems Corporation, Ann Arbor MI) in the real-time continuous measurement of arterial blood gases under different cardiocirculatory stress conditions METHODS: Inotropic stimulation (Dobutamine 2.5 and 5 µg/kg/min), vasoconstriction (Arginine-vasopressin 4, 8 and 16 IU/h), hemorrhage (-10%, -20%, -35%, and -50% of the theoretical volemia), and volume resuscitation were induced in ten swine (57.4 ± 10.7 Kg).Intermittent blood gas assessments were carried out using a routine gas analyzer at any experimental phase and compared with values obtained at the same time settings during continuous monitoring with CDI™ 500 system. The Bland-Altman analysis was employed. RESULTS: Bias and precision for pO2 were - 0.06 kPa and 0.22 kPa, respectively (r2 = 0.96); pCO2 - 0.02 kPa and 0.15 kPa, respectively; pH -0.001 and 0.01 units, respectively ( r2 = 0.96). The analysis showed very good agreement for SO2 (bias 0.04,precision 0.33, r2 = 0.95), Base excess (bias 0.04,precision 0.28, r2 = 0.98), HCO3 (bias 0.05,precision 0.62, r2 = 0.92),hemoglobin (bias 0.02,precision 0.23, r2 = 0.96) and K+ (bias 0.02, precision 0.27, r2 = 0.93). The sensor was reliable throughout the experiment during hemodynamic variations. CONCLUSIONS: Continuous blood gas analysis with the CDI™ 500 system was reliable and it might represent a new useful tool to accurately and timely monitor gas exchange in critically ill patients. Nonetheless, our findings need to be confirmed by larger studies to prove its reliability in the clinical setting.

Usefulness of the Cryolife O'Brien stentless suprannular aortic valve to prevent prosthesis-patient mismatch in the small aortic root.

OBJECTIVES: This study evaluated the occurrence of prosthesis-patient mismatch (PPM) after Cryolife O'Brien (CLOB) suprannular stentless valve replacement in patients with a small aortic root and its repercussions on the patient's hemodynamic status and left ventricular mass regression. BACKGROUND: The correct management of the small aortic annulus is still controversial. Small aortic prostheses can lead to a PPM, which results in high gradients with important repercussions on the hemodynamic status. METHODS: Seventy-two patients (mean age: 72.5 +/- 6.2 years, 73.6% women) with a small aortic root (< or =21 mm intraoperatively measured aortic annulus) had a CLOB valve implanted in the aortic position between November 1993 and July 2001 at our institution. Mean prosthesis size was 22.0 +/- 0.8 mm. Patients underwent echocardiography preoperatively, at discharge, six months, one year and yearly thereafter. RESULTS: The incidence of PPM at discharge was 22.2% (16/72); 18.7% were severe (effective orifice area index [EOAI] < or =0.65 cm/m(2)), 43.7% were moderate (EOAI = 0.66 to 0.75 cm/m(2)) and 37.6% were mild (0.76 to 0.85 cm/m(2)). At multivariable analysis, gender (p < 0.001), age (p = 0.015), body surface area (p < 0.001) and patient's annulus index (p < 0.001) were significant factors influencing the occurrence of "transient" PPM. At one year the incidence of PPM was 0%. CONCLUSIONS; Suprannular CLOB valve yielded excellent hemodynamic results in patients with small aortic roots. This study demonstrates that PPM can be completely avoided when using the CLOB valve. The superior hemodynamics of this stentless valve are likely to be related to its suprannular design.

Preliminary experience with the St. Jude Medical Regent mechanical heart valve in the aortic position: early in vivo hemodynamic results.

BACKGROUND: The St. Jude Medical Regent is a new generation mechanical aortic valve. METHODS: Between March 2000 and July 2001, this valve was implanted in the aortic position in 40 patients (21 men; mean age 59.1 +/- 9.0 years). Preoperatively, 24 patients (60%) were in New York Heart Association functional class III or IV. Eighteen patients (45%) underwent associated procedures. Mean valve size was 21.4 +/- 2.4 mm. The mean duration of follow-up was 8.5 +/- 4.5 months (range, 1 to 16 months). RESULTS: There were no operative deaths. Early complications included one reoperation for bleeding and one transient low output syndrome. Valve replacement was followed by a significant reduction in mean and peak transaortic gradients over time (p < 0.001) and analysis of variance failed to demonstrate statistical differences between valve size over time (p = not significant). A significant reduction in left ventricular hypertrophy occurred over time (p = 0.01) in all valve sizes (p = not significant between groups): baseline left ventricular mass index was 194 g/cm2; it reduced by 22 g/cm2 (p = 0.006) at discharge. Left ventricular mass index decreased from 172 +/- 55 g/cm2 to 156 +/- 44 g/cm2 (p = 0.03) from discharge to 2 months. Further reductions were not significant. Relative wall thickness decreased from 0.57 +/- 0.13 preoperatively to 0.42 +/- 0.06 at discharge (p = 0.001), and again at 2 months (-0.2; p = not significant), and at 1 year (-0.02; p = not significant). CONCLUSIONS: The early experience with the St. Jude Medical Regent valve has been satisfactory.

Left ventricular dyssynchrony is associated with recurrence of ischemic mitral regurgitation after restrictive annuloplasty.

BACKGROUND: In our study, we investigated the impact of papillary muscle systolic dyssynchrony (DYS-PAP) obtained by 2D speckle-tracking echocardiography (2D-STE) in the prediction of recurrent ischemic mitral regurgitation (MR) after restrictive annuloplasty. METHODS: The study population consisted of 524 consecutive patients who survived coronary artery bypass grafting (CABG) and restrictive annuloplasty, performed between 2001 and 2010 at 3 different Institutions and who met inclusion criteria. The assessment of DYS-PAP was performed preoperatively and at follow-up (median 45.3 months [IQR 26-67]) by 2D-STE in the apical four-chamber view for the anterolateral papillary muscle (ALPM) and apical long-axis view for the posteromedial papillary muscle (PMPM). RESULTS: Recurrence of MR (≥ 2+ in patients with no/trivial MR at discharge) was found in 112 patients (21.3%) at follow-up. Compared to patients without recurrence of MR, these patients had higher DYS-PAP values at baseline (60.6 ± 4.4 ms vs. 47.2 ± 2.9 ms, p<0.001) which significantly worsened at follow-up (74.4 ± 5.2 ms, p=0.002 vs. baseline). In contrast, in patients with no MR recurrence, DYS-PAP was significantly reduced (25.3 ± 4.4 ms, p=0.002 vs. baseline). At logistic regression analysis DYS-PAP (odds ratio [OR]: 4.8, 95% Confidence Interval [CI]: 3.4-8.2, p<0.001), was the strongest predictor of recurrent MR with a cutoff ≥ 58 ms (95%CI 51-66 ms). The model showed an area under the Receiver Operating Characteristic (ROC) curve of 0.97 (CI 0.94-0.99 [optimism-corrected 0.94; CI 0.89-0.95]) with 98% sensitivity (CI 96-100% [optimism-corrected 95%; CI 91-96%]) and 90% specificity (CI 85-94% [optimism-corrected 87%; CI 82-90%]). CONCLUSIONS: DYS-PAP represents a reliable tool to identify patients with ischemic MR who can benefit from restrictive annuloplasty.

Minimally invasive mitral valve surgery: a systematic review.

In the recent years minimally invasive mitral valve surgery (MIMVS) has become a well-established and increasingly used option for managing patients with a mitral valve pathology. Nonetheless, whether the purported benefits of MIMVS translate into clinically important outcomes remains controversial. Therefore, in this paper we provide an overview of MIMVS and discuss results, morbidity, mortality, and quality of life following mitral minimally invasive procedures. MIMVS has been proven to be a feasible alternative to the conventional full sternotomy approach with low perioperative morbidity and short-term mortality. Reported benefits of MIMVS include also decreased postoperative pain, improved postoperative respiratory function, reduced surgical trauma, and greater patient satisfaction. Finally, compared to standard surgery, MIMVS demonstrated comparable efficacy across a range of long-term efficacy measures such as freedom from reoperation and long-term survival.

Emergency surgery for native mitral valve endocarditis: the impact of septic and cardiogenic shock.

BACKGROUND: Limited information exists about the real impact of the etiology of shock on early and late outcome after emergency surgery in acute native mitral valve endocarditis (ANMVE). This multicenter study analyzed the impact of the etiology of shock on early and late outcome in patients with ANMVE. METHODS: Data were collected in eight institutions. Three hundred-seventy-nine ANMVE patients undergoing surgery on an emergency basis between May 1991 and December 2009 were eligible for the study. According to current criteria used for the differential diagnosis of shock, patients were retrospectively assigned to one of three groups: group 1, no shock (n=154), group 2, cardiogenic shock (CS [n=118]), and group 3, septic shock (SS [n=107]). Median follow-up was 69.8 months. RESULTS: Early mortality was significantly higher in patients with SS (p<0.001). At multivariable logistic regression analysis, compared with patients with CS, patients with SS had more than 3.8 times higher risk of death. That rose to more than 4 times versus patients without shock. In addition, patients with SS had 4.2 times and 4.3 times higher risk of complications compared with patients with CS and without shock, respectively. Sepsis was also an independent predictor of prolonged artificial ventilation (p=0.04) and stroke (p=0.003) whereas CS was associated with a higher postoperative occurrence of low output syndrome and myocardial infarction (p<0.001). No difference was detected between groups in 18-year survival, freedom from endocarditis, and freedom from reoperation. CONCLUSIONS: Our study suggests that emergency surgery for ANMVE in patients with CS achieved satisfactory early and late results. In contrast, the presence of SS was linked to dismal early prognosis. Our findings need to be confirmed by further larger studies.

Increased coronary blood flow and cardiac contractile efficiency with intraaortic balloon counterpulsation in a porcine model of myocardial ischemia-reperfusion injury.

The evaluation of the impact of intraaortic balloon pump (IABP) on postischemic coronary perfusion and myocardial contractile impairment has been so far limited to early reperfusion phase. Therefore, we analyzed the 24-hour effects of IABP on coronary blood flow (CBF) and left ventricular performance in an animal model of acute myocardial ischemia-reperfusion injury. Healthy swine (n = 20) underwent 120-minute ligation of the left anterior descending coronary artery followed by 24 hours of reperfusion. We randomly assigned the animals to have IABP placed in the descending aorta 5 minutes after reperfusion onset (n = 10) or to undergo no implantation (n = 10). We measured CBF, coronary resistance, cardiac cycle efficiency (CCE), and maximal pressure/time ratio before ischemia was induced and at 30 minutes and 1, 6, 12, and 24 hours after reperfusion began. During diastole, CBF was significantly increased in IABP compared with baseline and controls at all time points (all p < 0.001). This was also true during systole in IABP only for the first hour after reperfusion began. Additionally, both CCE and pressure/time ratio were significantly increased in IABP compared with baseline at 30 minutes and 1 hour after reperfusion began (p < 0.001). IABP was associated with enhanced CBF and cardiac efficiency in a model of acute ischemic-reperfusion injury.

Pharmacological management of atrial fibrillation: one, none, one hundred thousand.

atrial fibrillation (AF) is associated with a significant burden of morbidity and increased risk of mortality. Antiarrhythmic drug therapy remains a cornerstone to restore and maintain sinus rhythm for patients with paroxysmal and persistent AF based on current guidelines. However, conventional drugs have limited efficacy, present problematic risks of proarrhythmia and cause significant noncardiac organ toxicity. Thus, inadequacies in current therapies for atrial fibrillation have made new drug development crucial. New antiarrhythmic drugs and new anticoagulant agents have changed the current management of AF. This paper summarizes the available evidence regarding the efficacy of medications used for acute management of AF, rhythm and ventricular rate control, and stroke prevention in patients with atrial fibrillation and focuses on the current pharmacological agents.

Impact of prophylactic intra-aortic balloon counter-pulsation on postoperative outcome in high-risk cardiac surgery patients: a multicentre, propensity-score analysis.

OBJECTIVE: The aim of this multicentre study was to determine whether the prophylactic use of intra-aortic balloon pump (IABP) translates into better early and long-term results in high-risk patients undergoing cardiac surgery. METHODS: From January 2000 to March 2009, 6121 high-risk patients (EuroSCORE >8), at six different institutions, underwent cardiac surgery. Propensity-score computer matching was performed, based on 10 variables representing patients characteristics and preoperative risk factors to correct for and minimise selection bias (Hosmer-Lemeshow goodness of fit, p=0.3; c=0.94). A total of 956 patients were successfully matched and consisted of 478 pairs either undergoing preoperative IABP (group A) or not receiving IABP preoperatively (group B). RESULTS: Multivariate logistic regression (odds ratio) revealed that group B had a 64% higher risk of in-hospital mortality (p=0.001), 57% higher risk of 30-day mortality (p=0.003), 45% higher risk of perioperative myocardial infarction (p=0.01), 57% higher risk of postoperative low-output syndrome (p=0.003), 45% higher risk of intensive care unit (ICU) length of stay (p=0.001) and 44% higher risk of hospital length of stay (p=0.001). Patients in group A showed, at follow-up, significant improvements in left ventricular (LV) ejection fraction (p<0.001), wall-motion score index (p<0.001) and LV dimensions (p<0.001). Five- and 8-year survivals did not differ between groups (5-year survival: 91.7 ± 3.1% vs 95 ± 2.1% in groups A and B, respectively, log-rank p=0.34; 8-year survival: 84.3 ± 5.5% vs 85.9 ± 6.1% in groups A and B, respectively, log-rank p=0.2). CONCLUSIONS: Prophylactic IABP support, in this multicentre experience, was showed to enhance perioperative management and outcome of high-risk cardiac surgery patients.

Early in vivo hemodynamic results after aortic valve replacement with the St Jude Medical Regent mechanical heart valve in patients with pure aortic stenosis.

BACKGROUND: The St Jude Medical Regent is a new-generation mechanical heart valve that represents a design evolution of the St Jude Hemodynamic Plus Series (HP). The purpose of this study was to evaluate early "in vivo" hemodynamic performance of the Regent valve in patients with aortic stenosis. METHODS: Between March 2000 and December 2001, 32 patients (mean age 59.9 +/- 5.9,56.3% male) with pure aortic stenosis received a Regent mechanical prosthesis in the aortic position. Hemodynamic performance was assessed by Doppler echocardiography at discharge, two months, six months, and one year by calculating peak transprosthetic velocity (Vmax), mean (MG) and peak (PG) transprosthetic gradients, effective orifice area index (EOAI), left ventricular mass index (LVMI), and degree of aortic regurgitation. RESULTS: A significant reduction in mean and peak transaortic gradients (p < 0.001) and a significant increase in EOAI (p < 0.001) over time followed valve replacement, and a bivariate analysis of variance (ANOVA) failed to demonstrate statistical differences by valve size over time (p = ns). A significant reduction in left ventricular hypertrophy occurred over time (p < 0.001) in all valve sizes (p = ns between groups): baseline LVMI was 221 +/- 57 g/cm2; it decreased by 30 g/cm2 (p < 0.001) at discharge. LVMI decreased from 191 +/- 54 g/cm2 to 161 +/- 41 g/cm2 (p < 0.001) from discharge to two months. Further reductions were not significant. At the six-month follow-up no patient in our cohort exhibited moderate or severe aortic regurgitation at Doppler echocardiography. CONCLUSIONS: Early results with the St Jude Medical Regent valve have been satisfactory. Further assessments are necessary to confirm these results.