Efstratios I. Charitos

Long-term outcomes after surgical ablation for atrial fibrillation in patients with continuous heart rhythm monitoring devices.

OBJECTIVESnSurgical ablation for atrial fibrillation (AF) is an established therapy for the treatment of concomitant AF in cardiac surgery patients. We aim to present our prospective experience with 99 continuously monitored patients and investigate whether enhanced monitoring can identify patterns and factors influencing AF recurrence after surgical AF ablation.nnnMETHODSnNinety-nine patients (73 males; age: 68.0 ± 9.2 years) with documented preoperative AF (paroxysmal: 29; persistent: 18; long-lasting persistent: 52, mean preoperative duration: 46 ± 53 months) underwent concomitant biatrial surgical ablation (Cox Maze III: 29), full set left atrial cryoablation (n = 22), high-intensity focused ultrasound (HIFU) box lesion (n = 46) or right-sided ablation (n = 2). Postoperative rhythm disclosure was provided via an implantable device. Scheduled follow-up was performed quarterly (mean ± standard deviation: 1.75 ± 1.16 years, 173.7 patient-years).nnnRESULTSnThe mean postoperative AF burden during the follow-up was 7 ± 19% (median: 0.2%). Seventy-one and 82 patients had AF burden <1% and <5%, respectively. The preoperative AF duration, preoperative ejection fraction, mitral valve surgery and HIFU in patients with more persistent AF were associated with statistically significant higher postoperative AF burdens. The pattern of AF recurrence during the 3-month blanking period was associated with the amount of later AF recurrence.nnnCONCLUSIONSnContinuous rhythm disclosure reveals that very small amounts of AF burden after surgical ablation are common. The preoperative duration of AF and the use of a box lesion only in patients with longer AF persistence history were independently associated with higher postoperative AF burden recurrence. The temporal AF pattern during the blanking period after ablation should be considered for further patient management and might serve as a prognostic factor.

Preoperative plasma growth-differentiation factor-15 for prediction of acute kidney injury in patients undergoing cardiac surgery

BackgroundGrowth-differentiation factor-15 (GDF-15) is an emerging humoral marker for risk stratification in cardiovascular disease. Cardiac-surgery-associated acute kidney injury (CSA-AKI), an important complication in patients undergoing cardiac surgery, is associated with poor prognosis. The present secondary analysis of an observational cohort study aimed to determine the role of GDF-15 in predicting CSA-AKI compared with the Cleveland-Clinic Acute Renal Failure (CC-ARF) score and a logistic regression model including variables associated with renal dysfunction.MethodsPreoperative plasma GDF-15 was determined in 1176 consecutive patients undergoing elective cardiac surgery. Patients with chronic kidney disease stage 5 were excluded. AKI was defined according to Kidney-Disease-Improving-Global-Outcomes (KDIGO) - creatinine criteria. The following variables were screened for association with development of postoperative AKI: age, gender, additive Euroscore, serum creatinine, duration of cardiopulmonary bypass, duration of surgery, type of surgery, total circulatory arrest, preoperative hemoglobin, preoperative oxygen-supplemented cerebral oxygen saturation, diabetes mellitus, hemofiltration during ECC, plasma GDF-15, high sensitivity troponin T (hsTNT), and N-terminal prohormone of B-type natriuretic peptide (NTproBNP).ResultsThere were 258 patients (21.9xa0%) with AKI (AKI stage 1 (AKI-1), nu2009=u2009175 (14.9xa0%); AKI-2, nu2009=u20096 (0.5xa0%); AKI-3, nu2009=u200977 (6.5xa0%)). The incidence of AKI-1 and AKI-3 increased significantly from the lowest to the highest tertiles of GDF-15. In logistic regression, preoperative GDF-15, additive Euroscore, age, plasma creatinine, diabetes mellitus, and duration of cardiopulmonary bypass were independently associated with AKI. Inclusion of GDF-15 in a logistic regression model comprising these variables significantly increased the area under the curve (AUC 0.738 without and 0.750 with GDF-15 included) and the net reclassification ability to predict AKI. Comparably, in receiver operating characteristic analysis the predictive capacity of the CC-ARF score (AUC 0.628) was improved by adding GDF-15 (AUC 0.684) but this score also had lower predictability than the logistic regression model. In random forest analyses the predictive capacity of GDF-15 was especially pronounced in patients with normal plasma creatinine.ConclusionThis suggests that preoperative plasma GDF-15 independently predicts postoperative AKI in patients undergoing elective cardiac surgery and is particularly helpful for risk stratification in patients with normal creatinine.Trial registrationNCT01166360 on July 20, 2010.

In vitro coronary flow after transcatheter aortic valve-in-valve implantation: A comparison of 2 valves

Background: Transcatheter aortic valve‐in‐valve implantation (TAVI‐ViV) is an evolving treatment strategy for degenerated surgical aortic valve bioprostheses (SAVBs). However, there is some concern regarding coronary obstruction, especially after TAVI‐ViV in calcified SAVBs with externally mounted leaflets. We investigated in vitro coronary flow and hydrodynamics after TAVI‐ViV using 2 modern SAVBs with externally and internally mounted leaflets. Methods: Aortic root models including known risk factors for coronary obstruction served for the implantation of SAVBs with either externally mounted leaflets (St Jude Trifecta, size 25) or internally mounted leaflets (Edwards Perimount Magna Ease, size 25). Left and right coronary flow, as well as hydrodynamic parameters, were measured before and after TAVI‐ViV with an Edwards Sapien XT transcatheter heart valve, size 23. After the first experimental run, the SAVB leaflets were artificially “calcified,” and the measurements were repeated. Results: In both models, noncalcified and calcified, there was no significant reduction in coronary flow with either the Trifecta or the Perimount Magna Ease SAVB. After TAVI‐ViV, in the noncalcified model, the mean pressure gradient was increased (Trifecta, P = .0001; Perimount Magna Ease, P = .006) and the geometric orifice area was decreased (P < .001 for both), whereas in the calcified model, the mean pressure gradient was decreased (P < .001 for both) and the geometric orifice area was increased (P < .001 for both). Conclusions: In our specific model, in noncalcified as well as calcified conditions, TAVI‐ViV is feasible with either SAVB (Trifecta or Perimount Magna Ease) without an increased risk of coronary obstruction. Nevertheless, before clinical application of these results, thorough preoperative assessment, considering the different limitations of this model, is mandatory.

Decellularized Versus Standard Pulmonary Allografts in the Ross Procedure: Propensity-Matched Analysis

BACKGROUNDnIt is hypothesized that decellularization of allografts used for right ventricular outflow tract reconstruction may result in decreased valve deterioration. This study compared the durability of fresh decellularized pulmonary allografts with standard cryopreserved pulmonary allografts in patients undergoing the Ross procedure.nnnMETHODSnThe Ross procedure was performed in 144 patients with decellularized allografts (DA) from 2005 to 2014 and in 619 with standard cryopreserved allografts (SCA) from 1990 to 2014. Propensity score matching was used to compare early and midterm clinical outcome and echocardiographic allograft function over time between the two groups.nnnRESULTSnWe matched 94 DA patients (79.3% male; median age, 34.0 years; mean follow-up, 2.4 ± 1.9 years) to 94 SCA patients (78.3% male; median age, 35.0 years; mean follow-up, 9.4 ± 4.2 years). There were no significant differences in baseline characteristics after matching. The matched DA vs SCA groups, respectively, were comparable in actuarial 5-year freedom from allograft dysfunction (85.6% [95% confidence interval {CI}, 53.9% to 96.2%] vs 93.3% [95% CI, 85.7% to 96.9%], pxa0= 0.892), freedom from allograft reintervention (98.8% [95% CI, 91.7% to 99.8%] vs 95.5% [95% CI, 88.5% to 98.3%], pxa0= 0.383), survival (95.3% [95% CI, 87.8% to 98.2%] vs 97.7% [95% CI, 91.3% to 99.4%], pxa0= 0.323), and event-free survival (83.5% [95% CI, 70.6% to 91.1%] vs 84.5% [95% CI, 75.2% to 90.5%], pxa0= 0.515). Longitudinal echocardiographic analyses showed a similarly modest increase in allograft gradient and regurgitation grades over time in both groups, although direct statistical comparison was not possible.nnnCONCLUSIONSnUp to 5 years of follow-up, DA and SCA used for right ventricular outflow tract reconstruction in the Ross procedure are associated with comparably excellent clinical and hemodynamic outcome. Longer follow-up and dedicated echocardiographic studies will shed light on the long-term performance of DAs.

Data Science Meets the Clinician: Challenges and Future Directions

In the last three decades a profound transformation of the medical profession has taken place. The modern clinician is required to consume vast amounts of information from clinical studies, critically reviewing evidence that may or may not lead to changes in clinical practice. The present article presents some challenges that this era of information poses to clinicians and patients.

The effects of systemic oxygenation on cerebral oxygen saturation and its relationship to mixed venous oxygen saturation: A prospective observational study comparison of the INVOS and ForeSight Elite cerebral oximeters

PurposeThe present study aimed to test the hypothesis that cerebral oxygen saturation (ScO2) measurements with the INVOS-5100-C and the ForeSight-Elite cerebral oximeters vary in their correlation with mixed venous oxygen saturation (SvO2) upon changes in systemic oxygenation in extubated cardiac surgical patients. Additionally, we aimed to elucidate whether the ScO2 measurements of both devices can be used interchangeably to detect reduced SvO2.MethodsForty-eight spontaneously breathing patients extubated after cardiac surgery were included in this prospective observational study. The patients were exposed to both high (10 oxygen L·min−1 via face mask) and low (room air) inspiratory oxygen concentrations. Bi-hemispherical ScO2 was determined with the INVOS and ForeSight Elite cerebral oximeters. The SvO2 was measured with a pulmonary artery catheter.ResultsSignificant changes in oxygen delivery, ScO2 (by both cerebral oximeters), and SvO2 were observed upon variation of oxygenation. The minimum mean (standard deviation) ScO2 (ScO2min) using the INVOS and ForeSight did not differ significantly during high oxygen delivery [63.1 (8.6) % vs 65.8 (4.7) %, respectively; P = 0.07], but during low oxygen delivery, the INVOS value was significantly lower than that of the ForeSight oximeter [56.7 (8.9) % vs 61.3 (4.4) %, respectively; P = 0.003]. Both devices differed in the correlation between ScO2min and SvO2 for the combined oxygenation data (0.59, INVOS vs 0.28, ForeSight; correlation difference, 0.31; Bonferroni-adjusted 95% confidence interval [CI], 0.08 to 0.54; P = 0.008). The receiver-operating curve analysis revealed an area under the curve of 0.83 (95% CI, 0.74 to 0.9; P = 0.005) for detecting an SvO2 below 50% by ScO2min with the INVOS and 0.51 (95% CI, 0.41 to 0.62; P = 0.92), respectively, with the ForeSight.ConclusionsThese findings suggest that the cerebral oximeters tested react differently to variations in systemic oxygenation and in their relationship with SvO2 and thus give different information on cardiopulmonary function. These findings raise doubt about whether these devices should be used interchangeably.RésuméObjectifCette étude a voulu tester l’hypothèse selon laquelle les mesures de la saturation cérébrale en oxygène (ScO2) avec les oxymètres cérébraux INVOS-5100-C et ForeSight-Elite varient dans leur corrélation avec la saturation veineuse mixte en oxygène (SvO2) au moment de changements d’oxygénation systémique chez des patients chirurgicaux cardiaques extubés. De plus, nous avons voulu élucider la question de savoir si les mesures de ScO2 effectuées par les deux dispositifs pouvaient être utilisées indifféremment pour détecteur une réduction de la SvO2.MéthodesQuarante-huit patients extubés respirant spontanément après une chirurgie cardiaque ont été inclus dans cette étude observationnelle prospective. Les patients ont été exposés à des concentrations inspiratoires en oxygène élevées (10xa0L·min−1 d’oxygène par masque facial) et basses (air ambiant). La ScO2 bi-hémisphérique a été déterminée au moyen des oxymètres cérébraux INVOS et ForeSight Elite. La SvO2 a été mesurée via un cathéter de l’artère pulmonaire.RésultatsDes changements significatifs de l’apport d’oxygène, de la ScO2 (selon les deux oxymètres cérébraux) et de la SvO2 ont été observés au moment du changement d’oxygénation. Les ScO2 moyennes minimums (écart-type) (ScO2min) obtenues avec INVOS et ForeSight n’étaient pas significativement différente au cours de l’administration d’oxygène à forte concentration (respectivement, 63,1xa0[8,6]xa0% contre 65,8xa0[4,7]xa0%; P = 0,07) tandis que pendant l’administration d’oxygène à faible concentration, la valeur indiquée par l’INVOS était significativement inférieure à celle de l’oxymètre ForeSight (respectivement, 56,7xa0[8,9]xa0% contre 61,3xa0[4,4]xa0%; Pxa0<xa00,003). Les deux dispositifs présentaient une corrélation différente entre la ScO2min et la SvO2 pour les données d’oxygénation combinées (INVOSxa0= 0,59 contre ForeSight = 0,28; différence de corrélation, 0,31; intervalle de confiance [IC] à 95xa0% [avec correction de Bonferroni]xa0: 0,08 à 0,54; Pxa0<xa00,008). L’analyse de la courbe d’efficacité du récepteur (ROC) a révélé une aire sous la courbe de 0,83 (IC à 95xa0%xa0: 0,74 à 0,9; P = 0,005) pour la détection d’une SvO2 inférieure de 50xa0% par ScO2min avec l’INVOS et de 0,51 (IC à 95xa0%xa0: 0,41 à 0,62; P = 0,92) avec le ForeSight.ConclusionsCes constatations suggèrent que les oxymètres cérébraux testés réagissent différemment aux variations d’oxygénation systémique et dans leurs rapports avec la SvO2; ils donnent donc des informations différentes sur la fonction cardiopulmonaire. Ces constatations remettent donc en question l’utilisation équivalente de ces dispositifs.