Gaba, Prakriti

Background: It is known that hypokalemia, hypocalcemia and hypomagnesemia cause a prolonged QTc interval and are associated with an increased risk of ventricular arrhythmias. However, there are limited data on optimal serum electrolytes for patients admitted to the coronary care unit (CCU). Objective: Here, we aimed to evaluate the relationship between serum potassium, ionized calcium and magnesium levels and in-hospital mortality in the CCU setting. Methods: This retrospective cohort study included 8,498 consecutive patients admitted to the CCU at an academic tertiary medical center from 2004 through 2013. The mean of serum electrolytes was categorized as <3.5, 3.5-<4.0, 4.0-<4.5 (reference), 4.5-<5.0, and ≥5.0 mEq/L for potassium; <4.4, 4.4-<4.6, 4.6-<4.8, 4.8-<5.0 (reference), and ≥5.0 mg/dL for ionized calcium; and <1.8, 1.8-<2.0, 2.0-<2.2 (reference), 2.2-<2.4, and ≥2.4 mg/dL for magnesium. Multivariate logistic regression analysis was used to determine the association between the mean of serum electrolytes and in-hospital mortality. Results: Of the 8,498 patients, 599 (7%) died during hospitalization. Relationship between mean serum potassium (U-shaped), ionized calcium (inverted J-shape) and magnesium (J-shaped) and in-hospital mortality was present in Figure. Serum potassium levels <3.5, 4.5-<5.0 and ≥5.0 mEq/L were independently associated with an increased risk of in-hospital mortality (adjusted OR 1.7 95% CI 1.1-2.5, OR 1.7 95% CI 1.3-2.2, and OR 3.4 95% CI 2.4-4.8, respectively), compared to the reference group. As for serum ionized calcium, the levels of <4.4, 4.4-<4.6, and 4.6-<4.8 mg/dL independently increased risk of mortality (adjusted OR 3.0 95% CI 2.3-4.0, OR 2.0 95% CI 1.5-2.6, and OR 1.4 95% CI, 1.1-1.8, respectively). As for serum magnesium, an only level above 2.4 mg/dL was associated with an increased mortality risk (OR 1.6 95% CI, 1.1-2.2). Conclusions: In the CCU setting, serum potassium 3.5-<4.5 mEq/L, ionized calcium ≥5.0 mg/dL and magnesium <2.4 mg/dL are associated with the lowest in-hospital mortality. These findings do not support supratherapeutic repletion of potassium and magnesium.

Background: Women have a higher rate of adverse events after mitral valve surgery. We sought to evaluate whether outcomes after transcatheter edge-to-edge repair intervention by sex have similar trends to mitral valve surgery. Methods: The primary outcome was 1-year major adverse events defined as a composite of all-cause mortality, stroke, and any bleeding in the overall study cohort. Patients who underwent transcatheter edge-to-edge repair for mitral regurgitation with the MitraClip system in the Society of Thoracic Surgery/American College of Cardiology Transcatheter Valve Therapy registry were evaluated. Linked administrative claims from the Centers for Medicare and Medicaid Services were used to evaluate 1-year clinical outcomes. Associations between sex and outcomes were evaluated using a multivariable logistic regression model for in-hospital outcomes and Cox model for 1-year outcomes. Results: From November 2013 to March 2017, 5295 patients, 47.6% (n=2523) of whom were female, underwent transcatheter edge-to-edge repair. Females were less likely to have >1 clip implanted ( P <0.001) and had a lower adjusted odds ratio of device success (adjusted odds ratio, 0.78 [95% CI, 0.67–0.90]), driven by lower odds of residual mitral gradient <5 mm Hg (adjusted odds ratio, 0.54 [CI, 0.46–0.63]) when compared with males. At 1-year follow-up, the primary outcome did not differ by sex. Female sex was associated with lower adjusted 1-year risk of all-cause mortality (adjusted hazard ratio, 0.80 [CI, 0.68–0.94]), but the adjusted 1-year risk of stroke and any bleeding did not differ by sex. Conclusions: No difference in composite outcome of all-cause mortality, stroke, and any bleeding was observed between females and males. Adjusted 1-year all-cause mortality was lower in females compared with males.

Background Right bundle‐branch block (RBBB) occurs in 0.2% to 1.3% of people and is considered a benign finding. However, some studies have suggested increased risk of cardiovascular morbidity and mortality. We sought to evaluate risk attributable to incidental RBBB in patients without prior diagnosis of cardiovascular disease (CVD). Methods and Results We reviewed the Mayo Clinic Integrated Stress Center database for exercise stress tests performed from 1993 to 2010. Patients with no known CVD—defined as absence of coronary disease, structural heart disease, heart failure, or cerebrovascular disease—were selected. Only Minnesota residents were included, all of whom had full mortality and outcomes data. There were 22 806 patients without CVD identified; 220 of whom (0.96%) had RBBB, followed for 6 to 23 years (mean 12.4±5.1). There were 8256 women (36.2%), mean age was 52±11 years; and 1837 deaths (8.05%), including 645 cardiovascular‐related deaths (2.83%), occurred over follow‐up. RBBB was predictive of all‐cause (hazard ratio [HR], 1.5; 95% CI, 1.1–2.0; P =0.0058) and cardiovascular‐related mortality (HR,1.7; 95% CI, 1.1–2.8; P =0.0178) after adjusting for age, sex, diabetes mellitus, hypertension, obesity, current and past history of smoking, and use of a heart rate‐lowering drug. Patients with RBBB exhibited more hypertension (34.1% versus 23.7%, P <0.0003), decreased functional aerobic capacity (82±25% versus 90±24%; P <0.0001), slower heart rate recovery (13.5±11.5 versus 17.1±9.4 bpm; P <0.0001), and more dyspnea (28.2% versus 22.4%; P <0.0399) on exercise testing. Conclusions Patients with RBBB without CVD have increased risk of all‐cause mortality, cardiovascular‐related mortality, and lower exercise tolerance. These data suggest RBBB may be a marker of early CVD and merit further prospective evaluation.

Background: Right ventricular systolic dysfunction (RVD) often coexists with various cardiopulmonary diseases. However, the association between RVD and risk of sudden cardiac death (SCD) has not been well studied. This study examined the risk of SCD associated with RVD in patients with heterogeneous underlying cardiac diseases. Methods: The Mayo Clinic cardiac care unit database included 5463 consecutive patients with complete echocardiographic evaluation to assess right ventricular systolic function and RVD severity. Prospective surveillance follow-up was obtained for all patients. SCD was adjudicated when a malignant ventricular arrhythmia was documented as the primary rhythm leading to death. RESULTS: The prevalence of mild RVD and moderate-severe RVD was 14.9% and 17.1%, respectively. Patients with RVD were more likely to have a history of congestive heart failure, cardiac arrest, pulmonary disease, and lower baseline left ventricular ejection fraction compared with those with normal right ventricular systolic function. During a median follow-up of 14 months, the incidence of SCD was highest in patients with moderate-severe RVD (7.4% versus 4.4% in mild RVD versus 1.6% in normal right ventricular function; P <0.001). After adjustment for baseline characteristics, mild RVD (adjusted hazard ratio, 1.57; P =0.046) and moderate-severe RVD (adjusted hazard ratio, 1.91; P =0.006) were independently associated with an increased risk of SCD. Moderate-severe RVD remained an independent predictor of SCD for patients with left ventricular ejection fraction >35% without or with preexisting implantable cardioverter-defibrillator (adjusted hazard ratio, 4.12; P =0.003 and adjusted hazard ratio, 5.04; P <0.001, respectively). Conclusions: Presence of RVD in patients with a history of preexisting cardiac disease is an independent predictor of SCD irrespective of left ventricular ejection fraction.

Background— People with heart failure and preserved ejection fraction develop increases in left ventricular (LV) end-diastolic pressures during exercise that contribute to dyspnea. In normal open-chest animal preparations, the pericardium restrains LV filling when central blood volume increases. We hypothesized that resection of the pericardium using a minimally invasive epicardial approach would mitigate the increase in LV end-diastolic pressure that develops during volume loading in normal and diseased hearts with the chest intact. Methods and Results— Invasive hemodynamic assessment was performed at baseline and after saline load before and after pericardial resection in normal canines with open (n=3) and closed chest (n=5) and in a pig model with features of human heart failure and preserved ejection fraction with sternum intact (n=4). In closed-chest animals, pericardiotomy was performed using a novel subxiphoid procedure. In both experimental preparations of normal dogs, pericardiotomy blunted the increase in LV end-diastolic pressure with saline infusion, while enhancing the saline-mediated increase in LV end-diastolic volume. With chest intact in the pig model, percutaneous pericardial resection again blunted the increase in LV end-diastolic pressure secondary to volume expansion (+4±3 versus +13±5 mm Hg; P =0.014), while enhancing the saline-mediated increase in LV end-diastolic volume (+17±1 versus +10±2 mL; P =0.016). Conclusions— This proof of concept study demonstrates that pericardial resection through a minimally invasive percutaneous approach mitigates the elevation in LV filling pressures with volume loading in both normal animals and a pig model with diastolic dysfunction. Further study is warranted to determine whether this method is safe and produces similar acute and chronic hemodynamic benefits in people with heart failure and preserved ejection fraction.

Percutaneous Pericardiotomy ToolIntroductionEpicardial procedures frequently require pericardial manipulation. We aimed to develop a nonsurgical percutaneous pericardial modification tool that may (1) facilitate epicardial‐based procedures by enabling adhesiolysis or (2) attenuate the myocardial constraining effect of the pericardium.MethodsThree novel devices were developed to enable pericardiotomy, all of which can be deployed in over‐the‐wire fashion following percutaneous epicardial access. The grasper permits us to seize the pericardial membrane providing leverage for incision. The scissors enables anterograde cutting maneuvers. The reverse‐slitter allows retrograde incisions; in addition, this device has a deflectable tip that increases the potential cutting area. We optimized these tools for safety by including electrodes to test for phrenic nerve stimulation as well as myocardial stimulation to determine directionality of the cutting devices. The base of the scissors and reverse‐slitter are also blunt ensuring that the cutting element is always away from the myocardium.ResultsFollowing 5 nonbeating heart bench test experiments for prototype development, 11 animal (9 canine, 2 swine) studies were performed. Of these 2 were proof‐of‐concept open chest studies; the remaining 9 were entirely closed‐chest, percutaneous procedures allowing for remodification of the prototypes. The tools successfully permitted incision of the pericardium in all studies. Hemodynamic measurements were assessed postincision and showed no compromise of systolic function. No coronary artery or phrenic nerve damage was seen in any study.ConclusionPercutaneous pericardiotomy is feasible and appears to be safe. It may provide leverage in epicardial‐based procedures and offer treatment options in disease processes characterized by pericardial restraint.

Abstract BACKGROUND: Patients with pleomorphic xanthoastrocytoma (PXA) routinely undergo multiple procedures to ensure recurrence-free survival and are resultantly at increased risk of experiencing perioperative complications (regional, medical, and/or neurological), a combination of which has not been recorded in previous studies. OBJECTIVE: To determine perioperative outcomes in a cohort of patients (adult and pediatric) with intracranial PXA. METHODS: We retrospectively identified 39 patients who underwent surgery at our institution for intracranial PXA between 1994 and 2011. Demographic factors were recorded along with Karnofsky Performance Status (KPS), complications, and mortality. RESULTS: Mean patient age was 31 years at the most recent surgery. A majority of patients (24; 62%) had multiple surgeries with a mean of 2 operations per patient. Eleven PXAs (28%) were malignant (grade III or IV). Perioperative complications included permanent neurological worsening in 4 patients (10%), regional complications in 4 (10%), and medical complications in 3 (8%). Preoperative KPS was ≥70 in 34 of 38 patients (89%). Long-term postoperative KPS was ≥70 in 36 of 37 patients (97%), suggesting good functional outcomes. There was no perioperative mortality, but 7 patients (18%) died of tumor progression. Patients with malignant PXAs trended toward higher risk of regional complications (3 of 11 patients [27%]; P = .06), received adjuvant therapy more often (10 of 11 patients [91%]; P < .001), had higher mortality from tumor progression (7 of 11 patients [64%]; P < .001), and were significantly larger (mean, 6.05 ± 0.73 cm standard error of the mean; n = 7; P < .01). CONCLUSION: Both pediatric and adult PXAs may be resected with good functional outcomes. Perioperative neurological complications are relatively common, but do not affect long-term functional outcome or mortality. Malignant PXAs are higher risk for perioperative complications and, ultimately, death from tumor progression, despite increased use of adjuvant radiation and chemotherapy.

BackgroundThe association of atypical nevi with melanoma and other forms of skin cancer has not been clearly defined.MethodsWe studied 631 patients with first lifetime diagnosis of mild, moderate or severely atypical nevus from 2000 through 2005, identified through a population‐based approach.ResultsAge at first diagnosis differed significantly between men and women (p<.001). Incidence rates peaked in the second through fourth decades in women and in the third, sixth and seventh decades in men. From 2000 through 2005, the overall age‐ and sex‐adjusted incidence rate of all degrees of atypical nevi was 76.0 per 100,000 person‐years. There were no statistically significant associations identified between the degree of atypia and the future development of basal cell carcinoma, squamous cell carcinoma or MM (p = 0.51, p = 0.28 and p = 0.19, respectively).ConclusionThere is no association between atypical nevi and the subsequent development of non‐melanoma skin cancer and MM. Incidence rates of atypical nevi are higher among younger women and older men. The association between degree of atypia and malignant melanoma warrants further study.