Association of Shock Index with Echocardiographic Parameters in Cardiac Intensive Care Unit

BACKGROUND

A high shock index (SI), the ratio of heart rate (HR) to systolic blood pressure (SBP), has been associated with unfavorable outcomes. We sought to determine the hemodynamic underpinnings of an elevated SI using 2-D and doppler Transthoracic Echocardiography (TTE) in unselected cardiac intensive care unit (CICU) patients.

METHODS

We included Mayo Clinic CICU admissions from 2007 to 2018 who were in sinus rhythm at the time of TTE. The SI was calculated using HR and SBP at the time of TTE. Patients were grouped according to SI: <0.7, 4012 (64%); 0.7-0.99, 1764 (28%); and ≥ 1.0, 513 (8%). Pearson's correlation coefficient was used to assess associations between continuous variables.

RESULTS

We included 6289 unique CICU patients, 58% of whom had acute coronary syndrome. The median age was 67.9 years old and 37.8% were females. The mean SI was 0.67 BPM/mmHg. As the SI increased, markers of left ventricular (LV) systolic function and forward flow decreased, including left ventricular ejection fraction (LVEF), fractional shortening, left ventricular outflow tract (LVOT) velocity time integral (VTI), stroke volume, LV stroke work index, and cardiac power output. Biventricular filling pressures increased, and markers of right ventricular function worsened with rising SI. Most TTE measurements reflecting LV function and forward flow were inversely correlated with SI, including LV stroke work index (r = -0.59) and LVOT VTI (r = -0.41), as were both systemic vascular resistance index (r = -0.43) and LVEF (r = -0.23).

CONCLUSION

CICU patients with elevated SI have worse biventricular function and systemic hemodynamics, particularly decreased stroke volume and related calculated TTE parameters. The SI is an easily available marker that can be used to identify CICU patients with unfavorable hemodynamics who may require further assessment.

Noninvasive Hemodynamic Characterization of Shock and Preshock Using Echocardiography in Cardiac Intensive Care Unit Patients

BACKGROUND

Shock and preshock are defined on the basis of the presence of hypotension, hypoperfusion, or both. We sought to determine the hemodynamic underpinnings of shock and preshock noninvasively using transthoracic echocardiography (TTE).

METHODS AND RESULTS

We included Mayo Clinic cardiac intensive care unit patients from 2007 to 2015 with TTE within 1 day of admission. Hypotension and hypoperfusion at the time of cardiac intensive care unit admission were used to define 4 groups. TTE findings were evaluated across these groups, and in-hospital mortality was evaluated according to TTE findings in each group. We included 5375 patients with a median age of 69.2 years (36.8% women). The median left ventricular ejection fraction was 50%. Groups based on hypotension and hypoperfusion were assigned as follows: no hypotension or hypoperfusion, 59.7%; isolated hypotension, 15.3%; isolated hypoperfusion, 16.4%; and both hypotension and hypoperfusion, 8.7%. Most TTE variables of interest varied across these groups, with worse biventricular function, lower forward flow, and higher filling pressures as the degree of hemodynamic compromise increased. In-hospital mortality occurred in 8.2%, and inpatient deaths had more TTE parameter abnormalities. In-hospital mortality increased with the degree of hemodynamic compromise, and a marked gradient in in-hospital mortality was observed when the clinical classification of shock and preshock was combined with TTE findings reflecting worse biventricular function, lower forward flow, or higher filling pressures.

CONCLUSIONS

Substantial differences in cardiac function are observed between cardiac intensive care unit patients with preshock and shock using TTE, and the combination of the clinical and TTE hemodynamic assessment provides robust mortality risk stratification.

Critical Care Cardiology Trials Network (CCCTN): a cohort profile

AIMS

The aims of the Critical Care Cardiology Trials Network (CCCTN) are to develop a registry to investigate the epidemiology of cardiac critical illness and to establish a multicentre research network to conduct randomised clinical trials (RCTs) in patients with cardiac critical illness.

METHODS AND RESULTS

The CCCTN was founded in 2017 with 16 centres and has grown to a research network of over 40 academic and clinical centres in the United States and Canada. Each centre enters data for consecutive cardiac intensive care unit (CICU) admissions for at least 2 months of each calendar year. More than 20 000 unique CICU admissions are now included in the CCCTN Registry. To date, scientific observations from the CCCTN Registry include description of variations in care, the epidemiology and outcomes of all CICU patients, as well as subsets of patients with specific disease states, such as shock, heart failure, renal dysfunction, and respiratory failure. The CCCTN has also characterised utilization patterns, including use of mechanical circulatory support in response to changes in the heart transplantation allocation system, and the use and impact of multidisciplinary shock teams. Over years of multicentre collaboration, the CCCTN has established a robust research network to facilitate multicentre registry-based randomised trials in patients with cardiac critical illness.

CONCLUSION

The CCCTN is a large, prospective registry dedicated to describing processes-of-care and expanding clinical knowledge in cardiac critical illness. The CCCTN will serve as an investigational platform from which to conduct randomised controlled trials in this important patient population.

Peripheral blood neutrophil-to-lymphocyte ratio is associated with mortality across the spectrum of cardiogenic shock severity

PURPOSE

To evaluate the association between the neutrophil-to-lymphocyte ratio (NLR) and mortality across the cardiogenic shock (CS) severity spectrum, defined using the Society of Cardiovascular Interventions and Angiography (SCAI) shock stages.

MATERIALS AND METHODS

We retrospectively analyzed cardiac intensive care unit (CICU) patients between 2007 and 2015. Predictors of in-hospital mortality were analyzed using logistic regression.

RESULTS

We included 8280 patients aged 67.3 ± 15.2 years (37.2% females). Elevated NLR (≥7) was present in 45% of patients. NLR increased with worsening SCAI stage and was associated with higher in-hospital mortality in shock stages A to C (all p < 0.001). After multivariable adjustment, NLR remained associated with higher in-hospital mortality (adjusted odds ratio 1.05 per 3.5 NLR units, 95% CI 1.03-1.08, p < 0.001), with an optimal cut-off of ≥7 (in-hospital mortality 13.1% vs. 4.1%, adjusted odds ratio 1.44, 95% CI 1.14-1.81, p = 0.002). Patients in SCAI stage A or B with NLR ≥7 had higher in-hospital mortality than patients in SCAI stage B or C with NLR <7, respectively.

CONCLUSIONS

Elevated NLR is associated with higher in-hospital mortality in CICU patients with or at risk for CS, emphasizing the importance of systemic inflammation as a determinant of outcomes in CS patients.

Noninvasive echocardiographic cardiac power output predicts mortality in cardiac intensive care unit patients

BACKGROUND

Low cardiac power output (CPO), measured invasively, can identify critically ill patients at increased risk of adverse outcomes, including mortality. We sought to determine whether non-invasive, echocardiographic CPO measurement was associated with mortality in cardiac intensive care unit (CICU) patients.

METHODS

Patients admitted to CICU between 2007 and 2018 with echocardiography performed within one day (before or after) admission and who had available data necessary for calculation of CPO were evaluated. Multivariable logistic regression determined the relationship between CPO and adjusted hospital mortality.

RESULTS

A total of 5,585 patients (age of 68.3 ± 14.8 years, 36.7% female) were evaluated with admission diagnoses including acute coronary syndrome (ACS) in 56.7%, heart failure (HF) in 50.1%, cardiac arrest (CA) in 12.2%, shock in 15.5%, and cardiogenic shock (CS) in 12.8%. The mean left ventricular ejection fraction (LVEF) was 47.3 ± 16.2%, and the mean CPO was 1.04 ± 0.37 W. There were 419 in-hospital deaths (7.5%). CPO was inversely associated with the risk of hospital mortality, an association that was consistent among patients with ACS, HF, and CS. On multivariable analysis, higher CPO was associated with reduced hospital mortality (OR 0.960 per 0.1 W, 95CI 0.0.926-0.996, P = .03). Hospital mortality was particularly high in patients with low CPO coupled with reduced LVEF, increased vasopressor requirements, or higher admission lactate.

CONCLUSIONS

Echocardiographic CPO was inversely associated with hospital mortality in unselected CICU patients, particularly among patients with increased lactate and vasopressor requirements. Routine calculation and reporting of CPO should be considered for echocardiograms performed in CICU patients.

Biventricular Function and Shock Severity Predict Mortality in Cardiac ICU Patients

BACKGROUND

Ventricular function, including left ventricular systolic dysfunction (LVSD), right ventricular systolic dysfunction (RVSD), and biventricular dysfunction (BVD), contribute to shock in cardiac ICU (CICU) patients, but the prognostic usefulness remains unclear.

RESEARCH QUESTION

Do patients with ventricular dysfunction have higher mortality at each Society for Cardiovascular Angiography and Intervention (SCAI) shock stage?

STUDY DESIGN AND METHODS

We identified patients in the CICU admitted with available echocardiography data. LVSD was defined as left ventricular ejection fraction < 40%, RVSD as moderate or greater systolic dysfunction by semiquantitative measurement, and BVD as the presence of both. Multivariate logistic regression determined the relationship between ventricular dysfunction and adjusted in-hospital mortality as a function of SCAI stage.

RESULTS

The study population included 3,158 patients with a mean ± SD age of 68.2 ± 14.6 years, of which 51.8% had acute coronary syndromes. LVSD was present in 22.3%, RVSD in 11.8%, and BVD in 16.4%. After adjustment for SCAI shock stage, no difference in in-hospital mortality was found between patients with LVSD or RVSD and those without ventricular dysfunction (P > .05), but BVD was associated independently with higher in-hospital mortality (adjusted hazard ratio, 1.815; 95% CI, 1.237-2.663; P = .0023). The addition of ventricular dysfunction to the SCAI staging criteria increased discrimination for hospital mortality (area under the receiver operating characteristic curve, 0.784 vs 0.766; P < .001).

INTERPRETATION

Among patients admitted to the CICU, only BVD was associated independently with higher hospital mortality. The addition of echocardiography assessment to the SCAI shock criteria may facilitate improved clinical risk stratification.

Association between sepsis survivorship and long-term cardiovascular outcomes in adults: a systematic review and meta-analysis

PURPOSE

We aimed to determine the association between sepsis and long-term cardiovascular events.

METHODS

We conducted a systematic review of observational studies evaluating post-sepsis cardiovascular outcomes in adult sepsis survivors. MEDLINE, Embase, and the Cochrane Controlled Trials Register and Database of Systematic Reviews were searched from inception until April 21st, 2021. Two reviewers independently extracted individual study data and evaluated risk of bias. Random-effects models estimated the pooled crude cumulative incidence and adjusted hazard ratios (aHRs) of cardiovascular events compared to either non-septic hospital survivors or population controls. Primary outcomes included myocardial infarction, stroke, and congestive heart failure; outcomes were analysed at maximum reported follow-up (from 30 days to beyond 5 years post-discharge).

RESULTS

Of 12,649 screened citations, 27 studies (25 cohort studies, 2 case-crossover studies) were included with a median of 4,289 (IQR 502-68,125) sepsis survivors and 18,399 (IQR 4,028-83,506) controls per study. The pooled cumulative incidence of myocardial infarction, stroke, and heart failure in sepsis survivors ranged from 3 to 9% at longest reported follow-up. Sepsis was associated with a higher long-term risk of myocardial infarction (aHR 1.77 [95% CI 1.26 to 2.48]; low certainty), stroke (aHR 1.67 [95% CI 1.37 to 2.05]; low certainty), and congestive heart failure (aHR 1.65 [95% CI 1.46 to 1.86]; very low certainty) compared to non-sepsis controls.

CONCLUSIONS

Surviving sepsis may be associated with a long-term, excess hazard of late cardiovascular events which may persist for at least 5 years following hospital discharge.

Shock in the cardiac intensive care unit: Changes in epidemiology and prognosis over time

There are few studies documenting the changing epidemiology and outcomes of shock in cardiac intensive care unit (CICU) patients. We sought to describe the changes in shock epidemiology and outcomes over time in a CICU population.

METHODS

We included 1859 unique patients admitted to the Mayo Clinic Rochester CICU from 2007 through 2018 with an admission diagnosis of shock. Temporal trends, including mortality, were assessed across 3-year periods.

RESULTS

Shock comprised 15.1% of CICU admissions during the study period, increasing from 8.8% of CICU admissions in 2007 to 21.6% in 2018 (P < .01 for trend). Mean age was 68 ± 14 years (38% females). Shock was cardiogenic in 65%, septic in 10% and mixed cardiogenic-septic in 15%. Concomitant diagnoses in patients with cardiogenic shock (CS) included acute coronary syndrome (ACS) in 17%, heart failure (HF) in 35% and both in 40%. There was no significant change in the prevalence of individual shock subtypes over time (P > .1). Among patients with CS, the prevalence of ACS decreased and the prevalence of HF increased over time (P < .01). Hospital mortality was highest among patients with mixed shock (39%; P = .05). Among patients with CS, hospital mortality was lower among those with HF compared to those without HF (31% vs. 40%, P < .01). Hospital mortality decreased over time among patients with shock (P < .01) and CS (P = .02).

CONCLUSIONS

The prevalence of shock in the CICU has increased over time, with a substantial prevalence of mixed CS. The etiology of CS has changed over the last decade with HF overtaking ACS as the most common cause of CS in the CICU.

Percutaneous Closure of a Giant Aortic Pseudoaneurysm Using Multimodality Imaging Guidance

Ascending aortic pseudoaneurysm is a rare, life-threatening complication of cardiac surgery. Surgical management is recommended, however, transcatheter techniques offer a less invasive alternative. We describe successful percutaneous closure, guided by using multimodality imaging, in a patient with high surgical risk.

Defining Shock and Preshock for Mortality Risk Stratification in Cardiac Intensive Care Unit Patients

BACKGROUND

Previous studies have defined preshock as isolated hypotension or isolated hypoperfusion, whereas shock has been variably defined as hypoperfusion with or without hypotension. We aimed to evaluate the mortality risk associated with hypotension and hypoperfusion at the time of admission in a cardiac intensive care unit population.

METHODS

We analyzed Mayo Clinic cardiac intensive care unit patients admitted between 2007 and 2015. Hypotension was defined as systolic blood pressure <90 mm Hg or mean arterial pressure <60 mm Hg, and hypoperfusion as admission lactate >2 mmol/L, oliguria, or rising creatinine. Associations between hypotension and hypoperfusion with hospital mortality were estimated using multivariable logistic regression.

RESULTS

Among 10 004 patients with a median age of 69 years, 43.1% had acute coronary syndrome, and 46.1% had heart failure. Isolated hypotension was present in 16.7%, isolated hypoperfusion in 15.3%, and 8.7% had both hypotension and hypoperfusion. Stepwise increases in hospital mortality were observed with hypotension and hypoperfusion compared with neither hypotension nor hypoperfusion (3.3%; all P<0.001): isolated hypotension, 9.3% (adjusted odds ratio, 1.7 [95% CI, 1.4-2.2]); isolated hypoperfusion, 17.2% (adjusted odds ratio, 2.3 [95% CI, 1.9-3.0]); both hypotension and hypoperfusion, 33.8% (adjusted odds ratio, 2.8 [95% CI, 2.1-3.6]). Adjusted hospital mortality in patients with isolated hypoperfusion was higher than in patients with isolated hypotension (P=0.02) and not significant different from patients with both hypotension and hypoperfusion (P=0.18).

CONCLUSIONS

Hypotension and hypoperfusion are both associated with increased mortality in cardiac intensive care unit patients. Hospital mortality is higher with isolated hypoperfusion or concomitant hypotension and hypoperfusion (classic shock). We contend that preshock should refer to isolated hypotension without hypoperfusion, while patients with hypoperfusion can be considered to have shock, irrespective of blood pressure.

Association between mean arterial pressure during the first 24 hours and hospital mortality in patients with cardiogenic shock

Background

The optimal MAP target for patients with cardiogenic shock (CS) remains unknown. We sought to determine the relationship between mean arterial pressure (MAP) and mortality in the cardiac intensive care unit (CICU) patients with CS.

Methods

Using a single-center database of CICU patients admitted between 2007 and 2015, we identified patients with an admission diagnosis of CS. MAP was measured every 15 min, and the mean of all MAP values during the first 24 h (mMAP₂₄) was recorded. Multivariable logistic regression determined the relationship between mMAP₂₄ and adjusted hospital mortality.

Results

We included 1002 patients with a mean age of 68 ± 13.7 years, including 36% females. Admission diagnoses included acute coronary syndrome in 60%, heart failure in 74%, and cardiac arrest in 38%. Vasoactive drugs were used in 72%. The mMAP₂₄ was higher (75 vs. 71 mmHg, p < 0.001) among hospital survivors (66%) compared with non-survivors (34%). Hospital mortality was inversely associated with mMAP₂₄ (adjusted OR 0.9 per 5 mmHg higher mMAP₂₄, p = 0.01), with a stepwise increase in hospital mortality at lower mMAP₂₄. Patients with mMAP₂₄ < 65 mmHg were at higher risk of hospital mortality (57% vs. 28%, adjusted OR 2.0, 95% CI 1.4–3.0, p < 0.001); no differences were observed between patients with mMAP₂₄ 65–74 vs. ≥ 75 mmHg (p > 0.1).

Conclusion

In patients with CS, we observed an inverse relationship between mMAP₂₄ and hospital mortality. The poor outcomes in patients with mMAP₂₄ < 65 mmHg provide indirect evidence supporting a MAP goal of 65 mmHg for patients with CS.

Comprehensive Cardiac Care After Cardiac Arrest

Cardiac arrest (CA) results in multiorgan ischemia until return of spontaneous circulation and often is followed by a low-flow shock state. Upon restoration of circulation and organ perfusion, resuscitative teams must act quickly to achieve clinical stability while simultaneously addressing the underlying etiology of the initial event. Optimal cardiovascular care demands focused management of the post-cardiac arrest syndrome and associated shock. Acute coronary syndrome should be considered and managed in a timely manner, because early revascularization improves patient outcomes and may suppress refractory arrhythmias. This review outlines the diagnostic and therapeutic considerations that define optimal cardiovascular care after CA.

The Basics of ARDS Mechanical Ventilatory Care for Cardiovascular Specialists

The ongoing COVID-19 pandemic has placed pressure on health care systems and intensive care unit capacity worldwide. Respiratory insufficiency is the most common reason for hospital admission in patients with COVID-19. The most severe form of respiratory failure is acute respiratory distress syndrome (ARDS), which is associated with significant morbidity and mortality. Patients with ARDS are often treated with invasive mechanical ventilation according to established evidence-based and guideline recommended management strategies. With growing strain on critical care capacity, clinicians from diverse backgrounds, including cardiovascular specialists, might be required to help care for the growing number of patients with severe respiratory failure and ARDS. The aim of this article is to outline the fundamentals of ARDS diagnosis and management, including mechanical ventilation, for the nonintensivist. In the absence of mechanical ventilation trials specifically in patients with COVID-19-associated ARDS, the information presented is on the basis of general ARDS trials.

National Interhospital Transfer for Patients With Acute Cardiovascular Conditions

Background

Treatment of ST-elevation myocardial infarction (STEMI) in Canada is protocolized, and timely patient transfer can improve outcomes. Population-based processes of care in Canada for other cardiovascular conditions remain less clear. We aimed to describe the interhospital transfer of Canadian patients with acute cardiovascular disease.

Methods

We reviewed the Canadian Institute for Health Information Discharge Abstract Database for adult patients hospitalized with acute cardiovascular disease between 2013 and 2018. We compared patient characteristics and clinical outcomes based on transfer status (transferred, nontransferred) and presenting hospital (teaching, large community, medium community, and small community hospitals). The primary outcome of interest was in-hospital mortality.

Results

There were 476,753 patients with primary acute cardiovascular diagnoses, 48,579 (10.2%) of whom were transferred. Transferred patients were more frequently younger, male, and had fewer comorbidities. The most common diagnoses among transferred patients were non-STEMI (44.2%), STEMI (29.0%), and congestive heart failure (9.4%). Using teaching hospitals as a reference, transfer to large and medium community hospitals was associated with lower hospital mortality (adjusted odds ratio: 0.83, 95% confidence interval: 0.75-0.91 and 0.45, 95% confidence interval: 0.39-0.52, respectively).

Conclusions

Approximately 10% of patients with acute cardiovascular conditions are transferred to another hospital. Patient transfer may be associated with lower in-hospital mortality, with possible variability based on diagnosis, comorbidities, hospital of origin, and destination hospital. Further investigation into the optimization of care for patients with acute cardiovascular disease, including transfer practices, is warranted as regionalized care models continue to develop.

Epidemiology of in-hospital cardiac arrest complicating non-ST-segment elevation myocardial infarction receiving early coronary angiography

In the period between 2000 and 2014, 584,704 admissions with non-ST-segment elevation myocardial infarction that received early coronary angiography (day zero) were identified from the National Inpatient Sample. In-hospital cardiac arrest was noted in 4349 (0.8%), of which ~47% were from ventricular arrhythmias and ~90% of occurred within ≤4 days. Non-ST-segment elevation myocardial infarction admissions with in-hospital cardiac arrest had higher in-hospital mortality compared to those without (61% vs. 1.6%) with an unchanged temporal trend of in-hospital cardiac arrest rates (adjusted odds ratio 1.29 [95% confidence interval 0.73-2.28]) in 2014 compared to 2000).

Anticoagulation with direct thrombin inhibitors during extracorporeal membrane oxygenation

Use of extracorporeal membrane oxygenation to support patients with critical cardiorespiratory illness is increasing. Systemic anticoagulation is an essential element in the care of extracorporeal membrane oxygenation patients. While unfractionated heparin is the most commonly used agent, unfractionated heparin is associated with several unique complications that can be catastrophic in critically ill patients, including heparin-induced thrombocytopenia and acquired antithrombin deficiency. These complications can result in thrombotic events and subtherapeutic anticoagulation. Direct thrombin inhibitors (DTIs) are emerging as alternative anticoagulants in patients supported by extracorporeal membrane oxygenation. Increasing evidence supports DTIs use as safe and effective in extracorporeal membrane oxygenation patients with and without heparin-induced thrombocytopenia. This review outlines the pharmacology, dosing strategies and available protocols, monitoring parameters, and special use considerations for all available DTIs in extracorporeal membrane oxygenation patients. The advantages and disadvantages of DTIs in extracorporeal membrane oxygenation relative to unfractionated heparin will be described.

Prevention of venous thrombosis after electrophysiology procedures: a survey of national practice

PURPOSE

Femoral venous access is required for most electrophysiology procedures. Limited data are available regarding post-procedure venous thromboembolism (VTE), specifically deep vein thrombosis (DVT) and pulmonary embolism (PE). Potential preventative strategies are unclear. We aimed to survey Canadian centers regarding incidence of VTE and strategies for prevention of VTE after procedures that do not require post-procedure anticoagulation.

METHODS

An online survey was distributed to electrophysiologists representing major Canadian EP centers. Participants responded regarding procedural volume, incidence of VTE post-procedure, and their practice regarding pharmacological and non-pharmacological peri-procedural VTE prophylaxis.

RESULTS

The survey included 17 centers that performed a total of 6062 procedures in 2016. Ten patients (0.16%) had VTE (including 9 DVTs and 6 PEs) after diagnostic electrophysiology studies and right-sided ablation procedures excluding atrial flutter. Five centers (41.6%) administered systemic intravenous heparin during both diagnostic electrophysiology studies and right-sided ablation procedures. For patients taking oral anticoagulants, 10 centers (58.8%) suspend therapy prior to the procedure. Two centers (11.8%) routinely prescribed post-procedure pharmacologic prophylaxis for VTE. Four centers (23.5%) used compression dressings post-procedure and all prescribed bed rest for a maximum of 6 h. Of the variables collected in the survey, none were found to be predictive of VTE.

CONCLUSIONS

VTE is not a common complication of EP procedures. There is significant variability in the strategies used to prevent VTE events. Future research is required to evaluate strategies to reduce the risk of VTE that may be incorporated into EP practice guidelines.

Defining the pattern of initiation of monomorphic ventricular tachycardia using the beat-to-beat intervals recorded on implantable cardioverter defibrillators from the RAFT study: A computer-based algorithm

Arrhythmia onset pattern may have important implications on morbidity, recurrent implantable cardioverter defibrillator (ICD) shocks, and mortality, given the proposed correlation between initiation pattern and arrhythmia mechanism. Therefore, we developed and tested a computer-based algorithm to differentiate the pattern of initiation based on the beat-to-beat intervals of the ventricular tachycardia (VT) episodes in ICD recordings from the Resynchronization-Defibrillation for Ambulatory Heart Failure Trial (RAFT). Intervals on intracardiac electrograms from ICDs were analyzed backwards starting from the marker of VT detection, comparing each interval with the average tachycardia cycle length. If the morphology of the beat initiating the VT was similar to the morphology of the VT itself, the episode was considered sudden. If the morphology of the beat initiating the VT was not similar to the morphology of the VT itself, the episode was considered non-sudden. The capability of the algorithm to classify the pattern of initiation based only on the beat-to-beat intervals allows for the classification and analysis of large datasets to further investigate the clinical importance of classifying VT initiation. If analysis of the VT initiation proves to be of clinical value, this algorithm could potentially be integrated into ICD software, which would make it easily accessible and potentially helpful in clinical decision-making.

Venous Thrombosis After Electrophysiology Procedures: A Systematic Review

BACKGROUND

Femoral venous access for catheter introduction represents the cornerstone of electrophysiology (EP) procedures. Limited data are available regarding postprocedure VTE. The aim of this systematic review is to determine the incidence of DVT and pulmonary embolism (PE) associated with femoral vein catheterization during EP procedures.

METHODS

An electronic search was conducted for studies documenting the incidence of DVT and PE after EP procedures. Studies were classified as atrial fibrillation (AF) or non-AF ablation procedures.

RESULTS

Two thousand eight-hundred sixty-four studies were evaluated, 16 of which were included in the analysis. The incidence of DVT after AF and non-AF ablations reached as high as 0.33% and 2.38%, respectively, with a pooled incidence of 0% (95% CI, 0%-0.0003%) and 0.24% (95% CI, 0.08%-0.39%), respectively. The incidence of PE was 0.29% after AF ablation and ranged from 0% to 1.67% for non-AF procedures; the pooled incidence after non-AF ablations was 0.12% (95% CI, 0%-0.25%). Asymptomatic DVT was documented in up to 21.2% of patients. Hematomas occurred in 1.05% of AF ablations (95% CI, 0.30%-1.8%) and 0.3% of non-AF ablations (95% CI, 0.09%-0.51%).

CONCLUSIONS

A lower incidence of symptomatic DVT and PE was observed after AF ablations as opposed to non-AF ablations, likely due to the use of routine periprocedural anticoagulation. Asymptomatic DVTs appear to be common, although their significance is unclear. Future studies are required to weigh the risk of hematoma against the risk of VTE associated with the use of prophylactic anticoagulation after non-AF ablation procedures.

Right ventricular ST-elevation myocardial infarction as a cause of death in idiopathic pulmonary arterial hypertension

A 32-year-old woman with advanced idiopathic pulmonary arterial hypertension (PAH), treated with oral tadalafil and intravenous epoprostenol, presented with typical angina pectoris of one day’s duration. Her electrocardiogram, previously typical of pulmonary hypertension, revealed an acute ST-elevation myocardial infarction in the anterior precordial leads. She had a prior coronary angiogram, in preparation for lung transplantation, that revealed normal coronary arteries. Urgent coronary angiography showed acute occlusion of several acute marginal coronary branches that feed the right ventricle (RV). Coronary angioplasty and stenting was unable to adequately restore coronary perfusion. Despite support, she developed progressive cardiogenic shock and died three days later. This is an unusual complication of PAH.

Pattern of initiation of monomorphic ventricular tachycardia and implications on tachycardia mechanism

The incidence of sudden cardiac death, predominantly caused by ventricular tachycardia and ventricular fibrillation, is high in patients with congestive heart failure. Implantable cardiac defibrillators have improved survival in this population but defibrillator shocks can lead to low quality of life and heart failure progression. The current management of recurrent ventricular tachycardia includes ablation and anti-arrhythmic drugs and both are associated with high recurrence rates. Better understanding the mechanism of ventricular tachycardia allowing individualization of treatment may improve outcomes. Re-entry is currently accepted as the mechanism of the majority of monomorphic ventricular tachycardias in patients with congestive heart failure, being responsible for more than 90% of the ventricular tachycardia in patients with ischemic cardiomyopathy. On the other hand, some studies show a greater participation of focal arrhythmias in the genesis of ventricular tachycardia in this population. The pattern of initiation of ventricular tachycardia is divided into sudden, when the first beat of the tachycardia is morphologically similar to the rest of the tachycardia, and non-sudden, when its morphology is dissimilar. An association between the pattern of the initiation and the mechanism of ventricular tachycardia has been proposed. The pattern of initiation of ventricular tachycardia is a readily available from data stored in current generation implantable cardiac defibrillators. The association with tachycardia mechanism may allow individualization of the therapy, however evidence is lacking and further research is required.

Latitude, sunshine, and human lactase phenotype distributions may contribute to geographic patterns of modern disease: the inflammatory bowel disease model

Countries with high lactase nonpersistence (LNP) or low lactase persistence (LP) populations have lower rates of some "western" diseases, mimicking the effects of sunshine and latitude. Inflammatory bowel disease (IBD), ie, Crohn's disease and ulcerative colitis, is putatively also influenced by sunshine. Recent availability of worldwide IBD rates and lactase distributions allows more extensive comparisons. The aim of this study was to evaluate the extent to which modern day lactase distributions interact with latitude, sunshine exposure, and IBD rates. National IBD rates, national distributions of LP/LNP, and population-weighted average national annual ultraviolet B exposure were obtained, estimated, or calculated from the literature. Negative binomial analysis was used to assess the relationship between the three parameters and IBD rates. Analyses for 55 countries were grouped in three geographic domains, ie, global, Europe, and non-Europe. In Europe, both latitude and ultraviolet B exposure correlate well with LP/LNP and IBD. In non-Europe, latitude and ultraviolet B exposure correlate weakly with LP/LNP, but the latter retains a more robust correlation with IBD. In univariate analysis, latitude, ultraviolet B exposure, and LP/LNP all had significant relationships with IBD. Multivariate analysis showed that lactase distributions provided the best model of fit for IBD. The model of IBD reveals the evolutionary effects of the human lactase divide, and suggests that latitude, ultraviolet B exposure, and LP/LNP mimic each other because LP/LNP follows latitudinal directions toward the equator. However, on a large scale, lactase patterns also follow lateral polarity. The effects of LP/LNP in disease are likely to involve complex interactions.

Dynamics of vitamin D in patients with mild or inactive inflammatory bowel disease and their families

BACKGROUND

25(OH) vitamin D levels may be low in patients with moderately or severely active inflammatory bowel diseases (IBD: Crohn's disease and Idiopathic Ulcerative Colitis) but this is less clear in patients with mild or inactive IBD. Furthermore there is limited information of any family influence on 25(OH) vitamin D levels in IBD. As a possible risk factor we hypothesize that vitamin D levels may also be low in families of IBD patients.

OBJECTIVES

To evaluate 25[OH] vitamin D levels in patients with IBD in remission or with mild activity. A second objective is to evaluate whether there are relationships within IBD family units of 25[OH] vitamin D and what are the influences associated with these levels.

METHODS

Participants underwent medical history, physical examination and a 114 item diet questionnaire. Serum 25[OH] vitamin D was measured, using a radioimmunoassay kit, (replete ≥ 75, insufficient 50-74, deficient < 25-50, or severely deficient < 25 nmol/L). Associations between 25[OH] vitamin D and twenty variables were evaluated using univariate regression. Multivariable analysis was also applied and intrafamilial dynamics were assessed.

RESULTS

55 patients and 48 controls with their respective families participated (N206). 25[OH] vitamin D levels between patients and controls were similar (71.2 ± 32.8 vs. 68.3 ±26.2 nmol/L). Vitamin D supplements significantly increased intake but correlation with serum 25[OH] vitamin D was significant only during non sunny months among patients. Within family units, patients' families had mean replete levels (82.3 ± 34.2 nmol/L) and a modest correlation emerged during sunny months between patients and family (r2 =0.209 p = 0.032). These relationships were less robust and non significant in controls and their families.

CONCLUSIONS

In patients with mild or inactive IBD 25[OH] vitamin D levels are less than ideal but are similar to controls. Taken together collectively, the results of this study suggest that patient family dynamics may be different in IBD units from that in control family units. However contrary to the hypothesis, intra familial vitamin D dynamics do not pose additional risks for development of IBD.

Field dependent eating and perception as a function of weight and sex

It was hypothesized that the greater influence of external cues on obese than on normal individuals' eating behavior is a manifestation of a generalized sensitivity to external cues. Responsivity of nut consumption to the external cue of shells on the nuts and responsivity of judgment of verticality to the external cue of a tilted visual field were assessed for male and female, obese and normal-weight subjects. As predicted, both obese subjects' nut consumption and their judgments of verticality were more influenced by external cues than were those of normals. Females' judgments of verticality were more influenced by external cues than males' were, but the sex differences in eating behavior were not statistically significant. A significant correlation between the field dependence of subjects' eating behavior and their judgments of verticality suggests that a single cause may generate sensitivity to external cues in these two diverse situations.