Endocarditis after transcatheter aortic valve replacement; a new nightmare in cardiac surgery.

Treatment of prosthetic valve endocarditis after transcatheter aortic valve replacement (TAVR) remains challenging. An increase in TAVR endocarditis is inevitable, especially with the extension of indications and implantation in low-risk patients. We present a case of complex surgical treatment of prosthetic valve endocarditis after TAVR.

The costs and effects of contrast-enhanced magnetic resonance angiography and digital substraction angiography on quality of life in patients with peripheral arterial disease.

BACKGROUND: Contrast-enhanced magnetic resonance angiography (MRA) and intra-arterial digital subtraction angiography (DSA) both have a high diagnostic performance in the imaging of peripheral arterial occlusive disease (PAOD). However, little is known about the effects of initial, preoperative imaging using MRA or DSA on quality of life (QoL) in relation to costs (cost-utility). PURPOSE: To compare cost-utility of treatment strategies using either MRA or DSA as the principal imaging tool, related to QoL, in patients with PAOD. MATERIAL AND METHODS: In a prospective subgroup analysis of patients randomized between MRA and DSA (n = 79) for preoperative imaging, QoL questionnaires (SF-36) were obtained at randomization and at 4-month follow-up. Cost-effectiveness from hospital perspective was subsequently compared between groups and the difference in gained or lost QoL per € spent assessed using bootstrap analysis. RESULTS: No difference in quality of life was found. A treatment trajectory employing MRA as the principal imaging modality was almost 20% cheaper, leading to a better cost-utility ratio in favor of MRA. CONCLUSION: A treatment plan for peripheral arterial occlusive disease employing MRA versus DSA as the principal imaging modality yields a better cost/QoL ratio for MRA.

Concomitant atrial fibrillation ablation in minimally invasive cardiac surgery.

Concomitant atrial fibrillation (AF) ablation in cardiac surgery effectively restores sinus rhythm and may reduce morbidity and mortality. Cardiac surgery has witnessed the transition from the historical Cox Maze procedure to more modern and less invasive approaches for concomitant AF treatment. As minimally invasive cardiac surgery gains traction, ablation methods and careful patient selection become crucial to optimize results. Emerging techniques, including bipolar epicardial radiofrequency and endo/epicardial cryoablation, are central to these advances, targeting specific arrhythmogenic areas within the atria. While pulmonary vein isolation (PVI) is essential, it may be insufficient for patients with persistent or longstanding persistent AF. In such cases, left atrial posterior wall isolation has proven beneficial. Furthermore, recent studies emphasize the significance of left atrial appendage occlusion in concurrent AF treatments, highlighting its role in stroke risk reduction. Notably, the left atrium remains the focal point for concomitant AF surgery over the right, primarily due to concerns like high pacemaker implantation rates and complexities of right atrial ablation sets. Although guidelines support its widespread use, concomitant AF ablation outcomes vary based on patient selection, surgeon's expertise, and clinical context and thus the Heart Team's input is crucial for individualized decisions. In the upcoming sections, we present our patient selection and a visual guide to our techniques for concomitant AF surgery in minimally invasive mitral valve, coronary artery bypass and aortic valve surgery.

Sutureless aortic valve replacement in a calcified homograft combined with mitral valve replacement.

BACKGROUND: Aortic valve replacement in a patient with an aortic homograft can be very challenging, especially when concomitant mitral valve surgery needs to be performed. CASE PRESENTATION: We report a case of implantation of a sutureless aortic valve bioprosthesis combined with mitral valve replacement in a patient with a severely calcified aortic homograft where conventional valve replacement was technically unfeasible. CONCLUSIONS: We believe that sutureless AVR is a viable option especially for young patients with a high surgical risk where conventional valve replacement cannot be achieved.

Aortic valve calcification as a predictor of location and severity of paravalvular regurgitation after transcatheter aortic valve implantation.

OBJECTIVES: To determine whether the location of aortic valve calcium (AVC) influences the location of paravalvular regurgitation (PR). PR is an adverse effect of transcatheter aortic valve implantation (TAVI) with a negative effect on long-term patient survival. The relationship between AVC and the occurrence of PR has been documented. However, the relationship between the distribution of AVC and the location of PR is still sparsely studied. The purpose of this study was to correlate severity and location of AVC with PR in patients treated with TAVI. METHODS: Fifty-six consecutive patients who underwent transaortic or transapical TAVI and had preoperative computed tomography scans were included in this retrospective study. The volume, mass and location of AVC was determined and compared between patients with and without PR using a non-parametric t-test. Postoperative echocardiography was performed to determine the presence and location of PR, which was associated with the cusp with highest AVC using a χ(2) test. RESULTS: Valve deployment was successful in all 56 patients. PR was present in 38 patients (68%) after TAVI. There was a non-significantly higher volume of AVC in the PR group [214 (70-418) vs 371 (254-606) cm(3), P = 0.15]. AVC mass was significantly higher in patients with PR than in patients without PR [282 (188-421) vs 142 (48-259) mg, respectively, P = 0.043]. The location of PR was determined in 36 of these patients. Of these 36 patients, PR occurred at the cusp with the highest AVC in 20 patients (56%, χ(2) P = 0.030). CONCLUSIONS: In our population, PR was associated with greater AVC mass. Moreover, the location of PR was associated with the cusp with the highest amount of AVC.

Aluminium foil for the prevention of post-amputation pain: a randomised, double-blinded, placebo-controlled, crossover trial.

INTRODUCTION: Phantom limb pain (PLP) is a painful sensation perceived in the missing limb after amputation. The underlying pathophysiology remains unclear. Until recently, only opioid analgesics have been proven to be effective in prospective studies. Anecdotally, patients with PLP employ self-help measures, sometimes including 'wrapping up' or rubbing their stump with aluminium foil for relief. Our hypothesis is that wrapping an amputation stump with aluminium foil perioperatively will prevent PLP in the postoperative period. METHODS: From September 2007 to September 2009, 32 consecutive patients were included in a crossover, double-blinded, randomised clinical trial. Perioperative fitting of an aluminium stump bandage was compared with a placebo paper foil. Scores were noted daily in a variable diary. The observation period was 2 weeks: in the first week participants were double blinded, and in the second week there was a change of bandage from aluminium to placebo or vice versa. A visual analogue scale (VAS) score was used as primary research variable. Secondary variables were use of analgesics, VAS measures of wound pain and the incidence of wound infections. Statistical analysis was done by means of Student's t-test for non-paired observations. RESULTS: Baseline characteristics were similar between groups. A period effect (p= 0.84) and treatment-period interaction (p = 0.79) were not present. There was no significant difference (mean difference 0.42) between both treatments in PLP VAS scores (95% CI -2.56 to -1.81, p = 0.71). VAS measure of wound pain showed no significant difference between both groups (mean difference 0.34, 95% CI -2.32 to -1.66, p = 0.72). Also, the other secondary endpoints did not differ. CONCLUSION: Patients receiving an aluminium foil stump wrapping do not experience less phantom pain than with a placebo.

Improved microcirculation in patients with an acute ST-elevation myocardial infarction treated with the Impella LP2.5 percutaneous left ventricular assist device.

BACKGROUND: Circulatory support during percutaneous coronary intervention (PCI) in patients with ST-element elevation myocardial infarction (STEMI) aims at maintaining hemodynamic stability and organ perfusion. However, continuous flow pumps may interfere with the normal pulsatile circulation and the microcirculatory function. Sidestream dark field (SDF) imaging allows the visualization of microvascular structure and function of tissue and may provide information regarding the efficacy of the circulatory support. METHODS: Sidestream dark field was used to study the sublingual microcirculation (MC) in six anterior STEMI patients treated with PCI; three patients received Impella LP2.5 percutaneous left ventricular support (Impella group) and three patients received no support (control group). MC was assessed at baseline, at 24, 48 and 72 h after PCI. Data were analyzed using a validated scoring method and the microvascular flow index (MFI) and perfused vessel density (PVD) were calculated. MC of three healthy controls was used as normalized standard. RESULTS: Normal MC depending on both functional capillary density (PVD) and flow velocity or quality (MFI), as observed in healthy controls, was only achieved in the Impella group and paralleled improvement in LV function. Functional capillary density in the control and Impella groups were respectively equal and above the level of healthy controls. The quality of microcirculatory flow only in the Impella group reached values of healthy controls. CONCLUSIONS: Microcirculation assessed by SDF improved in STEMI patients treated with the Impella LP2.5 to levels observed in healthy persons and remained suboptimal after 72 h in patients without support. Sublingual SDF to assess MC may serve as a monitor of effective myocardial recovery after PCI and optimization of organ perfusion.

A combined surgical and percutaneous approach through the axillary artery to introduce the Impella LP5.0 for short-term circulatory support.

We describe a novel axillary approach for insertion and usage of the Impella LP5.0, a low cost micro-axial flow pump, in five patients requiring circulatory support after acute ST-segment elevation myocardial infarction (STEMI). This alternative approach for implantation of the Impella LP5.0 has been proven simple, safe and feasible, and less invasive in severely compromised patients. Our hybrid, percutaneous and surgical, approach offered acute short-term circulatory support in STEMI patients with acute heart failure, allowing myocardial recovery or selection for long-term mechanical support.

Pacemaker current (I(f)) in the human sinoatrial node.

AIMS: Animal studies revealed that the hyperpolarization-activated pacemaker current, I(f), contributes to action potential (AP) generation in sinoatrial node (SAN) and significantly determines heart rate. I(f) is becoming a novel therapy target to modulate heart rate. Yet, no studies have demonstrated that I(f) is functionally present and contributes to pacemaking in human SAN. We aimed to study I(f) properties in human SAN. METHODS AND RESULTS: In a patient undergoing SAN excision, we identified SAN using epicardial activation mapping. From here, we isolated myocytes and recorded APs and I(f) using patch-clamp techniques. Pacemaker cells generated spontaneous APs (cycle length 828 +/- 15 ms) following slow diastolic depolarization, maximal diastolic potential - 61.7 +/- 4.3 mV, and maximal AP upstroke velocity 4.6 +/- 1.2 V/s. They exhibited an hyperpolarization-activated inward current, blocked by external Cs(+) (2 mmol/L), characterizing it as I(f). Fully-activated conductance was 75.2 +/- 3.8 pS/pF, reversal potential - 22.1 +/- 2.4 mV, and half-maximal activation voltage and slope factor of steady-state activation - 96.9 +/- 2.7 and - 8.8 +/- 0.5 mV. Activation time constant ranged from approximately 350 ms (-130 mV) to approximately 1 s (-100 mV), deactivation time constant 156 +/- 45 ms (-40 mV). The role of I(f) in pacemaker activity was demonstrated by slowing of pacemaker cell diastolic depolarization and beating rate by Cs(+). CONCLUSION: I(f) is functionally expressed in human SAN and probably contributes to pacemaking in human SAN.

Single cells isolated from human sinoatrial node: action potentials and numerical reconstruction of pacemaker current.

Pacemaker activity of the sinoatrial node has extensively been studied in laboratory animals of various species, but is virtually unexplored in man. Most experimental data have been obtained from rabbit, where the hyperpolarization-activated 'funny' current (If), also known as the 'pacemaker current', plays an important role in diastolic depolarization and thus in setting pacing rate. Recently, we isolated pacemaker cells from excised human sinoatrial node tissue, and recorded action potentials and If using the whole-cell patch-clamp technique in current clamp and voltage clamp mode, respectively. Single sinoatrial node pacemaker cells showed a spontaneous beating rate of 73 +/- 3 beats/min (mean +/- SEM, n = 3) with a remarkably slow diastolic depolarization. If was identified in voltage clamp experiments as the 2 mmol/L Cs+-sensitive inward current activating upon 2-s hyperpolarizing voltage clamp steps. The If reversal potential and (de)activation kinetics were similar to those in rabbit. However, the fully-activated If conductance was 3-4 times smaller than typically found in rabbit. Furthermore, the half-maximal activation voltage was approximately 20 mV more negative than in rabbit. These differences would both act to reduce the functional role of If in human pacemaker cells. To assess this functional role, we carried out a numerical reconstruction of the If time course during an experimentally recorded human sinoatrial node action potential, based on the obtained data on If amplitude and kinetics. This reconstruction revealed that If provides a small but significant inward current in the voltage range of diastolic depolarization. We conclude that human sinoatrial node pacemaker cells functionally express If and that this If contributes to pacemaking in human sinoatrial node.