Staged circumferential and ostial pulmonary vein ablation for the treatment of paroxysmal atrial fibrillation

BACKGROUND: Comparisons between segmental ostial disconnection of the pulmonary veins (PV) and circumferential ablation have produced conflicting results in patients with paroxysmal atrial fibrillation (AF). The aim of this study was to evaluate a staged ablation procedure, every step of which was assessed by means of AF inducibility. METHODS: Twenty-two patients with paroxysmal AF were subjected to three ablation stages during one session: (1) circumferential ablation around the PV ostia, (2) segmental ostial PV isolation, and (3) ablation of areas within the circumferential lines with fractionated electrograms or voltage >0.2 mV as well as linear ablation at the mitral isthmus and the left atrial roof. Endpoint of the procedure was noninducibility of AF at any stage. RESULTS: Average radiofrequency energy delivery, fluoroscopy, and procedure times were 43 +/- 11 minutes, 40 +/- 11 minutes, and 3.8 +/- 0.5 hours, respectively. At 6-months follow-up, four patients experienced recurrence of AF (18%), whereas two additional patients (9%) had left atrial arrhythmias not registered before the procedure. Ninety-five percent of the patients who did not have inducible AF (regardless of the stage of ablation at which noninducibility was achieved) were free of recurrent AF, as opposed to none of the patients in whom AF was inducible at the end of the procedure (log-rank test, P < 0.001). CONCLUSIONS: A staged ablation procedure combing circumferential and ostial PV ablation with AF noninducibilty as endpoint may result in high success rates without the need of prolonged ablation sessions in certain patients with paroxysmal atrial fibrillation.     

Meta-Analysis of Methicillin-Resistant Staphylococcus aureus Colonization and Risk of Infection in Dialysis Patients

Patients undergoing dialysis are particularly vulnerable to methicillin-resistant Staphylococcus aureus (MRSA) infections. We performed a meta-analysis of published studies to estimate the prevalence of MRSA colonization in dialysis patients, time trends, and long-term risk of subsequent MRSA infections. Our search of the PubMed and Embase databases returned 5743 nonduplicate citations, from which we identified 38 relevant studies that included data on 5596 dialysis patients. The estimated prevalence of MRSA colonization was 6.2% (95% confidence interval [95% CI], 4.2% to 8.5%). The prevalence increased over time but remained stable after 2000. Stratification of patients according to dialysis modality and setting revealed that 7.2% (95% CI, 4.9% to 9.9%) of patients on hemodialysis were colonized with MRSA compared with 1.3% (95% CI, 0.5% to 2.4%) of patients on peritoneal dialysis (P=0.01), and that a statistically significant difference existed in the percentage of colonized inpatients and outpatients (14.2% [95% CI, 8.0% to 21.8%] versus 5.4% [95% CI, 3.5% to 7.7%], respectively; P=0.04). Notably, the risk of developing MRSA infections increased among colonized hemodialysis patients compared with noncolonized patients (relative risk, 11.5 [95% CI, 4.7 to 28.0]). The long-term (6–20 months) probability of developing a MRSA infection was 19% among colonized hemodialysis patients compared with only 2% among noncolonized patients. In summary, 6.2% of dialysis patients are MRSA colonized, and the average prevalence of colonization has remained stable since 2000. Colonization in hemodialysis patients is associated with increased risk of MRSA infection.Invasive methicillin-resistant Staphylococcus aureus (MRSA) infections are associated with mortality that is as high as 30%.¹ ESRD patients have a 100-fold higher risk of MRSA infection compared with the general population.² Among 80,461 invasive MRSA infections in 2011, 15,169 (18.9%) were among dialysis patients.³ Although a significant proportion of S. aureus infections are of endogenous origin,⁴ the relative risk of MRSA infections in colonized patients in this population is largely unknown. Our aim is to comprehensively assess the available data and give a global picture of MRSA colonization among dialysis patients. In this systematic review and meta-analysis, we estimate the prevalence of MRSA colonization among ESRD patients on dialysis treatment and study the significance of MRSA colonization in this population.     

Useful animal models for the research of osteoarthritis

Osteoarthritis (OA) is a major cause of suffering for millions of people. Investigating the disease directly on humans may be challenging. The aim of the present study is to investigate the advantages and limitations of the animal models currently used in OA research. The animal models are divided into induced and spontaneous. Induced models are further subdivided into surgical and chemical models, according to the procedure used to induce OA. Surgical induction of OA is the most commonly used procedure, which alters the exerted strain on the joint and/or alter load bearing leading to instability of the joint and induction of OA. Chemical models are generated by intra-articular injection of modifying factors or by systemically administering noxious agents, such as quinolones. Spontaneous models include naturally occurring and genetic models. Naturally occurring OA is described in certain species, while genetic models are developed by gene manipulation. Overall, there is no single animal model that is ideal for studying degenerative OA. However, in the present review, an attempt is made to clarify the most appropriate use of each model.     

Indications and outcomes of enucleation versus formal pancreatectomy for pancreatic neuroendocrine tumors

BackgroundPancreatoduodenectomy (PD) or distal pancreatectomy (DP) are common procedures for patients with a pancreatic neuroendocrine tumor (pNET). Nevertheless, certain patients may benefit from a pancreas-preserving resection such as enucleation (EN). The aim of this study was to define the indications and differences in long-term outcomes among patients undergoing EN and PD/DP.MethodsPatients undergoing resection of a pNET between 1992 and 2016 were identified. Indications and outcomes were evaluated, and propensity score matching (PSM) analysis was performed to compare long-term outcomes between patients who underwent EN versus PD/DP.ResultsAmong 1034 patients, 143 (13.8%) underwent EN, 304 (29.4%) PD, and 587 (56.8%) DP. Indications for EN were small size (1.5 cm, IQR:1.0–1.9), functional tumors (58.0%) that were mainly insulinomas (51.7%). After PSM (n = 109 per group), incidence of postoperative pancreatic fistula (POPF) grade B/C was higher after EN (24.5%) compared with PD/DP (14.0%) (p = 0.049). Median recurrence-free survival (RFS) was comparable among patients who underwent EN (47 months, 95% CI:23–71) versus PD/DP (37 months, 95% CI: 33–47, p = 0.480).ConclusionComparable long-term outcomes were noted among patients who underwent EN versus PD/DP for pNET. The incidence of clinically significant POPF was higher after EN.     

Influence of aortic elastic properties on pulse pressure changes induced by rapid ventricular pacing

The mechanism of aortic pulse pressure decline induced by acute rapid ventricular pacing remains incompletely understood. It has been ascribed to changes in stroke volume or aortic compliance. This becomes more complicated by the dependence of aortic compliance on the level of the mean aortic pressure as well as the aortic wall properties. To test the role of such mechanical factors, aortic pressure-diameter hemodynamics, derived from simultaneous tip-micromanometer aortic pressure recordings and high-fidelity ultrasonic intravascular aortic diameter recordings, were measured in 15 normal subjects during and after abrupt cessation of rapid ventricular pacing (up to 160 bpm). Immediately after terminating the pacing, diastolic aortic pressure declined (–9%, from 87.4±1.2 to 79.5±1.7 mmHg,P<0.0001) while systolic aortic pressure increased (+19%, from 109.5±1.6 to 130.1±2.8 mmHg,P<0.0001). Thus, pulse pressure increased from 22.1±2.2 to 50.6±3.1 mmHg,P<0.0001. To quantify systolic and diastolic aortic pressure differences we compared the first postpaced beat (a) and the last paced beat (b). To estimate what the aortic pressure would have been for the paced beats had the aortic diameter differences due to the different heart rate not occurred we calculated the theoretical pressure of the paced beat P_b=E_b·D_a, where E_b was the instantaneous aortic elastance of the paced beat and D_a was the aortic diameter for the postpaced beat. The corrected pressure difference was then calculated by the following: P_cor=(D_a·E_b)–P_a. It was found that systolic P_cor was 25% of systolic P_raw and diastolic P_cor was 89% of diastolic P_raw. P_raw was the pressure difference between paced and spontaneous beat measured from the raw data. P_cor indicates the portion of P_raw that results from a change in aortic stiffness as a consequence of viscous behavior or aorto-ventricular coupling. These data indicate that the majority of diastolic pressure decline after pacing was terminated, may reflect a change in aortic stiffness while the majority of systolic pressure rise, and may be attributable to differences in hemodynamics alone.     

A clinical trial to evaluate the worth of preoperative multimodality therapy in patients with operable carcinoma of the rectum

PURPOSE: National Surgical Adjuvant Breast and Bowel Project Protocol R-03 was designed to determine the worth of preoperative chemotherapy and radiation therapy in the management of operable rectal cancer. METHODS: Thus far, 116 patients of an eventual 900 with primary operable rectal cancer have been randomized to receive multimodality therapy to begin preoperatively (59 patients) or identical therapy beginning after curative surgery (57). All patients received seven cycles of 5-fluorouracil (FU)/leucovorin (LV) chemotherapy. Cycles 1 and 4 through 7 used a high-dose weekly FU regimen. In Cycles 2 and 3, FU and low-dose LV chemotherapy was given during the first and fifth week of radiation therapy (5,040 cGy). The preoperative arm (Group 1) received the first three cycles of chemotherapy and all radiation therapy before surgery. The postoperative arm (Group 2) received all radiation and chemotherapy after surgery. Primary study end points included disease-free survival and survival. Secondary end points included local recurrence, primary tumor response to combination therapy, tumor downstaging, and sphincter preservation. RESULTS: Overall treatment-related toxicity was similar in both groups. Although seven preoperative patients had events after randomization that precluded surgery, eight events occurred during an equivalent follow-up period in the postoperative group. No patient was deemed inoperable because of progressive local disease. Sphincter-saving surgery was intended in 31 percent of Group 1 patients and 33 percent of Group 2 patients at the time of randomization. Such surgery was actually performed in 50 percent of the preoperatively treated patients and 33 percent of the postoperatively treated patients. The use of protective colostomy in patients undergoing sphincter-sparing surgery and the development of perioperative complications in all surgical patients were similar in both groups. There was evidence of tumor downstaging in evaluable patients under-going preoperative therapy, with 8 percent of Group 1 patients having had a pathologic complete response. CONCLUSION: These data do suggest that the preoperative chemotherapy and radiation therapy regimen used are, at least, as safe and tolerable as standard postoperative treatment. There is presently a trend to tumor downstaging and sphincter preservation in the preoperative arm. Whether this arm will have greater or lesser survival and long-term toxicity awaits the completion of this relevant study.Supported by National Cancer Institute Grants U10-CA-12027 and U10-CA-37377 and American Cancer Society Grant R-13.Read at the meeting of The American Society of Colon and Rectal Surgeons, Seattle, Washington, June 9 to 14, 1996.     

Differentiating Psoriatic Arthritis From Psoriasis Without Psoriatic Arthritis Using Novel Serum Biomarkers

Objective

There is a high prevalence of undiagnosed psoriatic arthritis (PsA) in patients with psoriasis. Identifying soluble biomarkers for PsA will help in screening psoriasis patients for appropriate rheumatology referral. We therefore aimed to investigate whether serum levels of novel markers previously discovered by quantitative mass spectrometric analysis of synovial fluid and skin biopsies performs better than the C‐reactive protein (CRP) level in differentiating PsA patients from those with psoriasis without PsA (PsC).

Methods

In this case–control study, serum samples were obtained from 100 subjects with PsA, 100 with PsC, and 100 healthy controls. Patients with PsA and PsC were group matched for age, sex, psoriasis duration, and Psoriasis Area and Severity Index and were not currently receiving biologic treatment. Using enzyme‐linked immunosorbent assay, 4 high‐priority markers (Mac‐2‐binding protein [M2BP], CD5‐like protein [CD5L], myeloperoxidase [MPO], and integrin β5 [ITGβ5]), as well as previously established markers (matrix metalloproteinase 3 [MMP‐3] and CRP level) were assayed. Data were analyzed using logistic regression. Receiver operating characteristic (ROC) curves were plotted.

Results

In comparisons to controls, CD5L, ITGβ5, M2BP, MPO, MMP‐3, and CRP level were independently associated with PsA, while only CD5L, M2BP, and MPO were independently associated with PsC alone. In comparisons to PsC, ITGβ5, M2BP, and CRP level were independently associated with PsA. ROC analysis of this model shows an area under the curve (AUC) of 0.85 (95% confidence interval [95% CI] 0.80–0.90). The model that included CRP level alone had an AUC of 0.71 (95% CI 0.64–0.78).

Conclusion

CD5L, ITGβ5, M2BP, MPO, MMP‐3, and CRP level are markers for PsA. The combination of ITGβ5, M2BP, and CRP level differentiates PsA from PsC, and performs better than CRP level alone.