Pericardiocentesis in Severe Pulmonary Arterial Hypertension Guided by a Pulmonary Artery Catheter.

Patients, often with underlying rheumatologic disease, may present with pericardial effusions in the setting of pulmonary hypertension (PHTN). Pericardial drainage in PHTN is associated with significant morbidity and mortality. We describe a patient with PHTN who developed cardiac tamponade that was managed safely and effectively with pulmonary artery catheter-guided pericardiocentesis.

Culprit-Only Revascularization, Single-Setting Complete Revascularization, and Staged Complete Revascularization in Acute Myocardial Infarction: Insights From a Mixed Treatment Comparison Meta-Analysis of Randomized Trials.

BACKGROUND: Complete revascularization improves cardiovascular outcomes compared with culprit-only revascularization in patients with acute myocardial infarction ([MI]; ST-segment-elevation MI or non-ST-segment-elevation MI) and multivessel coronary artery disease. However, the timing of complete revascularization (single-setting versus staged revascularization) is uncertain. The aim was to compare the outcomes of single-setting complete, staged complete, and culprit vessel-only revascularization in patients with acute MI and multivessel disease. METHODS: PubMed, EMBASE, and clinicaltrials.gov databases were searched for randomized controlled trials that compared 3 revascularization strategies. RESULTS: From 16 randomized controlled trials that randomized 11 876 patients with acute MI and multivessel disease, both single-setting complete and staged complete revascularization reduced primary outcome (cardiovascular mortality/MI; odds ratio [OR], 0.52 [95% CI, 0.41-0.65]; OR, 0.74 [95% CI, 0.62-0.88]), composite of all-cause mortality/MI (OR, 0.52 [95% CI, 0.40-0.67]; OR, 0.78 [95% CI, 0.67-0.91]), major adverse cardiovascular event (OR, 0.42 [95% CI, 0.32-0.56]; OR, 0.62 [95% CI, 0.47-0.82]), MI (OR, 0.39 [95% CI, 0.26-0.57]; OR, 0.73 [95% CI, 0.59-0.90]), and repeat revascularization (OR, 0.30 [95% CI, 0.18-0.47]; OR, 0.46 [95% CI, 0.30-0.71]) compared with culprit-only revascularization. Single-setting complete revascularization reduced cardiovascular mortality/MI (OR, 0.70 [95% CI, 0.55-0.91]), major adverse cardiovascular event (OR, 0.67 [95% CI, 0.50-0.91]), and all-cause mortality/MI driven by a lower risk of MI (OR, 0.53 [95% CI, 0.36-0.77]) compared with staged complete revascularization. Single-setting complete revascularization ranked number 1, followed by staged complete revascularization (number 2) and culprit-only revascularization (number 3) for all outcomes. The results were largely consistent in subgroup analysis comparing ST-segment-elevation MI versus non-ST-segment-elevation MI cohorts. CONCLUSIONS: Single-setting complete revascularization may offer the greatest reductions in cardiovascular events in patients with acute MI and multivessel disease. A large-scale randomized trial of single-setting complete versus staged complete revascularization is warranted to evaluate the optimal timing of complete revascularization.

Cardiometabolic Co-morbidity Burden and Circulating Biomarkers in Patients With Chronic Coronary Disease in the ISCHEMIA Trials.

Cardiometabolic co-morbidities, diabetes (DM), hypertension (HTN), and obesity contribute to cardiovascular disease. Circulating biomarkers facilitate prognostication for patients with cardiovascular disease. We explored the relation between cardiometabolic co-morbidity burden in patients with chronic coronary disease and biomarkers of myocardial stretch, injury, inflammation, and platelet activity. We analyzed participants from the International Study of Comparative Health Effectiveness with Medical and Invasive Approaches (ISCHEMIA) trials biorepository with plasma biomarkers (N-terminal probrain natriuretic peptide, high-sensitivity cardiac troponin T, high-sensitivity C-reactive protein, interleukin-6, soluble CD40 ligand, and growth differentiation factor-15) and clinical risk factors (hemoglobin A1c [HbA1c], systolic blood pressure [SBP], and body mass index [BMI]) at baseline. We defined cardiometabolic co-morbidities as DM, HTN, and obesity at baseline. Co-morbidity burden is characterized by the number and severity of co-morbidities. Controlled co-morbidities were defined as HbA1c <7% for those with DM, SBP <130 mm Hg for those with HTN, and BMI <30 kg/m2. Severely uncontrolled was defined as HbA1c ≥8%, SBP ≥160 mm Hg, and BMI ≥35 kg/m2. We performed linear regression analyses to examine the association between co-morbidity burden and log-transformed biomarker levels, adjusting for age, gender, estimated glomerular filtration rate controlled for hemodialysis, and left ventricular ejection fraction. A total of 752 participants (mean age 66 years, 19% women, 84% White) were included in this analysis. Self-reported Black race, current smokers, history of myocardial infarction, and heart failure had a greater cardiometabolic co-morbidity burden. The presence of ≥1 severely uncontrolled co-morbidity was associated with significantly higher baseline levels of high-sensitivity cardiac troponin T, high-sensitivity C-reactive protein, interleukin-6, and growth differentiation factor-15 than participants with no co-morbidities. In conclusion, increasing cardiometabolic co-morbidity burden in patients with chronic coronary disease is associated with higher levels of circulating biomarkers of myocardial injury and inflammation.

McConnell's sign predicts normotensive shock in patients with acute pulmonary embolism.

BACKGROUND: Patients with intermediate-risk pulmonary embolism (PE) and normotensive shock may have worse outcomes. However, diagnosis of normotensive shock requires invasive hemodynamics. Our objective was to assess the predictive value of McConnell's sign in identifying normotensive shock in patients with intermediate-risk PE. METHODS: Patients with intermediate-risk PE who underwent percutaneous mechanical thrombectomy between August 2020 and April 2023 at a large academic public hospital were included in the study. Normotensive shock was defined as systolic blood pressure ≥ 90 mmHg without vasopressor support with pre-procedural invasive measures of cardiac index ≤2.2 L/min/m2 and clinical evidence of hypoperfusion (i.e. elevated lactate, oliguria). The primary outcome was the association between McConnell's sign and normotensive shock. RESULTS: Those with McConnell's sign (29/40, 72.5 %) had higher heart rate (114 vs 99 beats/min, p = 0.008), higher rates of elevated lactate (86 % vs 55 %, p = 0.038), lower cardiac index (1.9 vs 3.1 L/min/m2, p = 0.003), and higher rates of normotensive shock (76 % vs 27 %, p = 0.005). McConnell's sign had a sensitivity of 88 % and specificity of 53 % for identifying intermediate-risk PE patients with normotensive shock. Patients with McConnell's sign had an increased odds (odds ratio 8.38, confidence interval: 1.73-40.53, p = 0.008; area under the curve 0.70, 95 % confidence interval: 0.56-0.85) of normotensive shock. CONCLUSION: This is the first study to suggest that McConnell's sign may identify those in the intermediate-risk group who are at risk for normotensive shock. Larger cohorts are needed to validate our findings.

Comparing Management Strategies in Patients With Clot-in-Transit.

BACKGROUND: Clot-in-transit is associated with high mortality, but optimal management strategies remain uncertain. The aim of this study was to compare the outcomes of different treatment strategies in patients with clot-in-transit. METHODS: This is a retrospective study of patients with documented clot-in-transit in the right heart on echocardiography across 2 institutions between January 2020 and October 2023. The primary outcome was a composite of in-hospital mortality, resuscitated cardiac arrest, or hemodynamic decompensation. RESULTS: Among 35 patients included in the study, 10 patients (28.6%) received anticoagulation alone and 2 patients (5.7%) received systemic thrombolysis, while 23 patients (65.7%) underwent catheter-based therapy (CBT; 22 mechanical thrombectomy and 1 catheter-directed thrombolysis). Over a median follow-up of 30 days, 9 patients (25.7%) experienced the primary composite outcome. Compared with anticoagulation alone, patients who received CBT or systemic thrombolysis had significantly lower rates of the primary composite outcome (12% versus 60%; log-rank P<0.001; hazard ratio, 0.13 [95% CI, 0.03-0.54]; P=0.005) including a lower rate of death (8% versus 50%; hazard ratio, 0.10 [95% CI, 0.02-0.55]; P=0.008), resuscitated cardiac arrest (4% versus 30%; hazard ratio, 0.12 [95% CI, 0.01-1.15]; P=0.067), or hemodynamic deterioration (4% versus 30%; hazard ratio, 0.12 [95% CI, 0.01-1.15]; P=0.067). CONCLUSIONS: In this study of CBT in patients with clot-in-transit, CBT or systemic thrombolysis was associated with a significantly lower rate of adverse clinical outcomes, including a lower rate of death compared with anticoagulation alone driven by the CBT group. CBT has the potential to improve outcomes. Further large-scale studies are needed to test these associations.

Outcomes with treatment interventions for clot-in-transit in patients with pulmonary embolism: a meta-analysis.

OBJECTIVES: Clot-in-transit (CIT) in patients with pulmonary embolism (PE) has been associated with a high mortality rate and poor prognosis. The aim of this study was to evaluate the pooled efficacy of each of the 4 interventions (anticoagulation [AC] alone, systemic thrombolytic [ST] therapy, surgical thrombectomy, and catheter-based thrombectomy [CBT]) using mortality as the primary outcome. METHODS: A time limited search until March 28, 2024 was conducted using PubMed (National Institutes of Health) and EMBASE (Elsevier) databases. RESULTS: Thirteen studies (6 retrospective, 4 non-randomized prospective, and 3 pooled studies of case-reports) were included in the calculation of weighted proportion of mortality, including a total of 492 patients with CIT and PE with a mean age of 60.6 years; 50.1% were males. ST was the most frequently used treatment intervention (38.2%), followed by surgical thrombectomy (33.8%), AC alone (22.6%), and CBT (5.9%). The unweighted mortality was highest with AC alone 32.4% (36/111), followed by surgical thrombectomy 23.2% (38/164), CBT 20.7% (6/29), and ST 13.8% (26/188). The weighted mortality for AC alone was 35% (95% CI, 21% to 49%; 12 studies), surgical thrombectomy was 31% (95% CI, 16% to 47%; 12 studies), CBT was 20% (95% CI, 6% to 34%; 3 studies), and ST was 12% (95% CI, 5% to 19%; 12 studies). CONCLUSIONS: In this meta-analysis of patients with CIT and PE, the highest mortality was observed with AC alone, followed by surgical thrombectomy, CBT, and ST therapy. However, there remains a need for randomized clinical trial data to determine the best treatment.

In-hospital and readmission outcomes of patients with cancer admitted for pulmonary embolism treated with or without catheter-based therapy.

BACKGROUND: Cancer patients are at risk of pulmonary embolism (PE). Catheter-based therapies (CBT) are novel reperfusion options for PE though data in patients with cancer is lacking. STUDY DESIGN AND METHODS: Patients with intermediate- or high-risk PE were identified using the National Readmission Database (NRD) from 2017 to 2020. Primary outcome were in-hospital death and 90-day readmission. Secondary outcomes were in-hospital bleeding, 90-day readmission for venous thromboembolism (VTE)-related or right heart failure-related reasons and bleeding. Propensity scores were estimated using logistic regression and inverse-probability treatment weighting (IPTW) was utilized to compare outcomes between CBT and no CBT as well as CBT versus systemic thrombolysis. RESULTS: A total of 7785 patients were included (2511 with high-risk PE) of whom 1045 (13.4%) were managed with CBT. After IPTW, CBT was associated with lower rates of index hospitalization death (OR 0.89, 95% CI 0.83-0.96) and 90-day readmission (HR 0.75, 95% CI 0.69-0.81) but higher rates of in-hospital bleeding (OR 1.11, 95% CI 1.03-1.20) which was predominantly post-procedural bleeding. CBT was associated with lower risk of major bleeding (20.8% vs 24.8%; OR 0.80, 95% CI 0.68-0.94) compared with systemic thrombolysis. INTERPRETATION: Among patients with cancer with intermediate or high-risk PE, CBT was associated with lower in-hospital death and 90-day readmission. CBT was also associated with decreased risk of index hospitalization major bleeding compared with systemic thrombolysis. Prospective, randomized trials with inclusion of patients with cancer are needed to confirm these findings.

Efficacy and safety of catheter-based thrombectomy versus catheter-directed thrombolysis in acute pulmonary embolism.

Data comparing catheter-based thrombectomy (CBT) and catheter-directed thrombolysis (CDT) in acute pulmonary embolism are lacking. To address this, we performed a meta-analysis of prospective and retrospective studies of CBT and compared it to performance goal rates of mortality and major bleeding from a recently published network meta-analysis. When compared with performance goal for CDT based on historical studies, CBT was noninferior for all-cause mortality (6.0% vs 6.87%; P-valueNI < .001), non-inferior and superior for major bleeding (4.9% vs 11%; P-valueNI < .001 and P < .001 for superiority).

One- versus three-month dual antiplatelet therapy in high bleeding risk patients undergoing percutaneous coronary intervention for non-ST-segment elevation acute coronary syndromes.

BACKGROUND: A short dual antiplatelet therapy (DAPT) duration has been proposed for patients at high bleeding risk (HBR) undergoing drug-eluting coronary stent (DES) implantation. Whether this strategy is safe and effective after a non-ST-segment elevation acute coronary syndrome (NSTE-ACS) remains uncertain. AIMS: We aimed to compare the impact of 1-month versus 3-month DAPT on clinical outcomes after DES implantation among HBR patients with or without NSTE-ACS. METHODS: This is a prespecified analysis from the XIENCE Short DAPT programme involving three prospective, international, single-arm studies evaluating the safety and efficacy of 1-month (XIENCE 28 USA and Global) or 3-month (XIENCE 90) DAPT among HBR patients after implantation of a cobalt-chromium everolimus-eluting stent. Ischaemic and bleeding outcomes associated with 1- versus 3-month DAPT were assessed according to clinical presentation using propensity score stratification. RESULTS: Of 3,364 HBR patients (1,392 on 1-month DAPT and 1,972 on 3-month DAPT), 1,164 (34.6%) underwent DES implantation for NSTE-ACS. At 12 months, the risk of the primary endpoint of death or myocardial infarction was similar between 1- and 3-month DAPT in patients with (hazard ratio [HR] 1.09, 95% confidence interval [CI]: 0.71-1.65) and without NSTE-ACS (HR 0.88, 95% CI: 0.63-1.23; p-interaction=0.34). The key secondary endpoint of Bleeding Academic Research Consortium (BARC) Type 2-5 bleeding was consistently reduced in both NSTE-ACS (HR 0.57, 95% CI: 0.37-0.88) and stable patients (HR 0.84, 95% CI: 0.61-1.15; p-interaction=0.15) with 1-month DAPT. CONCLUSIONS: Among HBR patients undergoing implantation of an everolimus-eluting stent, 1-month, compared to 3-month DAPT, was associated with similar ischaemic risk and reduced bleeding at 1 year, irrespective of clinical presentation.

Variation in Health Status With Invasive vs Conservative Management of Chronic Coronary Disease.

BACKGROUND: The ISCHEMIA trial found that patients with chronic coronary disease randomized to invasive strategy had better health status than those randomized to conservative strategy. It is unclear how best to translate these population-level results to individual patients. OBJECTIVES: The authors sought to identify patient characteristics associated with health status from invasive and conservative strategies, and develop a prediction algorithm for shared decision-making. METHODS: One-year disease-specific health status was assessed in ISCHEMIA with the Seattle Angina Questionnaire (SAQ) Summary Score (SAQ SS) and Angina Frequency, Physical Limitations (PL), and Quality of Life (QL) domains (range 0-100, higher = less angina/better health status). RESULTS: Among 4,617 patients from 320 sites in 37 countries, mean SAQ SS was 74.1 ± 18.9 at baseline and 85.7 ± 15.6 at 1 year. Lower baseline SAQ SS and younger age were associated with better 1-year health status with invasive strategy (P interaction = 0.009 and P interaction = 0.004, respectively). For the individual domains, there were significant treatment interactions for baseline SAQ score (Angina Frequency, PL), age (PL, QL), anterior ischemia (PL), and number of baseline antianginal medications (QL), with more benefit of invasive in patients with worse baseline health status, younger age, anterior ischemia, and on more antianginal medications. Parsimonious prediction models were developed for 1-year SAQ domains with invasive or conservative strategies to support shared decision-making. CONCLUSIONS: In the management of chronic coronary disease, individual patient characteristics are associated with 1-year health status, with younger age and poorer angina-related health status showing greater benefit from invasive management. This prediction algorithm can support the translation of the ISCHEMIA trial results to individual patients. (International Study of Comparative Health Effectiveness With Medical and Invasive Approaches [ISCHEMIA]; NCT01471522).

Percutaneous mechanical thrombectomy in acute pulmonary embolism: Outcomes from a safety-net hospital.

BACKGROUND: Our study aims to present clinical outcomes of mechanical thrombectomy (MT) in a safety-net hospital. METHODS: This is a retrospective study of intermediate or high-risk pulmonary embolism (PE) patients who underwent MT between October 2020 and May 2023. The primary outcome was 30-day mortality. RESULTS: Among 61 patients (mean age 57.6 years, 47% women, 57% Black) analyzed, 12 (19.7%) were classified as high-risk PE, and 49 (80.3%) were intermediate-risk PE. Of these patients, 62.3% had Medicaid or were uninsured, 50.8% lived in a high poverty zip code. The prevalence of normotensive shock in intermediate-risk PE patients was 62%. Immediate hemodynamic improvements included 7.4 mmHg mean drop in mean pulmonary artery pressure (-21.7%, p < 0.001) and 93% had normalization of their cardiac index postprocedure. Thirty-day mortality for the entire cohort was 5% (3 patients) and 0% when restricted to the intermediate-risk group. All 3 patients who died at 30 days presented with cardiac arrest. There were no differences in short-term mortality based on race, insurance type, citizenship status, or socioeconomic status. All-cause mortality at most recent follow up was 13.1% (mean follow up time of 13.4 ± 8.5 months). CONCLUSION: We extend the findings from prior studies that MT demonstrates a favorable safety profile with immediate improvement in hemodynamics and a low 30-day mortality in patients with acute PE, holding true even with relatively higher risk and more vulnerable population within a safety-net hospital.

A case report of sodium azide-induced myopericarditis.

Background: Sodium azide exposures are rare but can be lethal as the substance inhibits complex IV in the electron transport chain, blocking adenosine-triphosphate (ATP) synthesis. Sodium azide is mostly used as a propellant in vehicular airbags but is also used in laboratory, pharmacy, and industrial settings. No known antidote exists and its cardiotoxic effects are poorly described in the literature. Case summary: We describe the case of a 31-year-old patient with major depressive disorder presenting with altered mental status after ingestion of an unknown amount of sodium azide. Although initially chest pain free, she developed pleuritic chest pain 48 h after ingestion. This was accompanied by new diffuse ST elevations on the electrocardiogram and serum troponin elevations concerning for myopericarditis. Treatment was pursued with a 14-day course of colchicine resulting in complete symptom resolution within 4 days of treatment initiation. The patient's transthoracic echocardiogram was only notable for a preserved left ventricular ejection fraction (LVEF). Discussion: Cardiac toxicity after sodium azide ingestion usually occurs days after ingestion and has been previously described in the forms of heart failure with reduced ejection fraction complicated by cardiogenic shock. We describe the first case of sodium azide-induced myopericarditis with a preserved LVEF treated with colchicine. Colchicine is an established treatment for pericarditis, but its inhibition of endocytosis, an ATP-dependent cellular function, could be mechanistically relevant to this case.

Low left ventricular outflow tract velocity time integral predicts normotensive shock in patients with acute pulmonary embolism.

In this study, we found that a low LVOT VTI (<15 cm), a simple bedside point-of-care measurement, predicts normotensive shock in patients with acute intermediate-risk PE.

Catheter-based therapy for high-risk or intermediate-risk pulmonary embolism: death and re-hospitalization.

BACKGROUND AND AIMS: Catheter-based therapies (CBTs) have been developed as a treatment option in patients with pulmonary embolism (PE). There remains a paucity of data to inform decision-making in patients with intermediate-risk or high-risk PE. The aim of this study was to characterize in-hospital and readmission outcomes in patients with intermediate-risk or high-risk PE treated with vs. without CBT in a large retrospective registry. METHODS: Patients hospitalized with intermediate-risk or high-risk PE were identified using the 2017-20 National Readmission Database. In-hospital outcomes included death and bleeding and 30- and 90-day readmission outcomes including all-cause, venous thromboembolism (VTE)-related and bleeding-related readmissions. Inverse probability of treatment weighting (IPTW) was utilized to compare outcomes between CBT and no CBT. RESULTS: A total of 14 903 [2076 (13.9%) with CBT] and 42 829 [8824 (20.6%) with CBT] patients with high-risk and intermediate-risk PE were included, respectively. Prior to IPTW, patients with CBT were younger and less likely to have cancer and cardiac arrest, receive systemic thrombolysis, or be on mechanical ventilation. In the IPTW logistic regression model, CBT was associated with lower odds of in-hospital death in high-risk [odds ratio (OR) 0.83, 95% confidence interval (CI) 0.80-0.87] and intermediate-risk PE (OR 0.76, 95% CI 0.70-0.83). Patients with high-risk PE treated with CBT were associated with lower risk of 90-day all-cause [hazard ratio (HR) 0.77, 95% CI 0.71-0.83] and VTE (HR 0.46, 95% CI 0.34-0.63) readmission. Patients with intermediate-risk PE treated with CBT were associated with lower risk of 90-day all-cause (HR 0.75, 95% CI 0.72-0.79) and VTE (HR 0.66, 95% CI 0.57-0.76) readmission. CONCLUSIONS: Among patients with high-risk or intermediate-risk PE, CBT was associated with lower in-hospital death and 90-day readmission. Prospective, randomized trials are needed to confirm these findings.

Factors Associated With Coronary Angiography Performed Within 6 Months of Randomization to the Conservative Strategy in the ISCHEMIA Trial.

BACKGROUND: ISCHEMIA (International Study of Comparative Health Effectiveness With Medical and Invasive Approaches) did not find an overall reduction in cardiovascular events with an initial invasive versus conservative management strategy in chronic coronary disease; however, there were conservative strategy participants who underwent invasive coronary angiography early postrandomization (within 6 months). Identifying factors associated with angiography in conservative strategy participants will inform clinical decision-making in patients with chronic coronary disease. METHODS: Factors independently associated with angiography performed within 6 months of randomization were identified using Fine and Gray proportional subdistribution hazard models, including demographics, region of randomization, medical history, risk factor control, symptoms, ischemia severity, coronary anatomy based on protocol-mandated coronary computed tomography angiography, and medication use. RESULTS: Among 2591 conservative strategy participants, angiography within 6 months of randomization occurred in 8.7% (4.7% for a suspected primary end point event, 1.6% for persistent symptoms, and 2.6% due to protocol nonadherence) and was associated with the following baseline characteristics: enrollment in Europe versus Asia (hazard ratio [HR], 1.81 [95% CI, 1.14-2.86]), daily and weekly versus no angina (HR, 5.97 [95% CI, 2.78-12.86] and 2.63 [95% CI, 1.51-4.58], respectively), poor to fair versus good to excellent health status (HR, 2.02 [95% CI, 1.23-3.32]) assessed with Seattle Angina Questionnaire, and new/more frequent angina prerandomization (HR, 1.80 [95% CI, 1.34-2.40]). Baseline low-density lipoprotein cholesterol <70 mg/dL was associated with a lower risk of angiography (HR, 0.65 [95% CI, 0.46-0.91) but not baseline ischemia severity nor the presence of multivessel or proximal left anterior descending artery stenosis >70% on coronary computed tomography angiography. CONCLUSIONS: Among ISCHEMIA participants randomized to the conservative strategy, angiography within 6 months of randomization was performed in <10% of patients. It was associated with frequent or increasing baseline angina and poor quality of life but not with objective markers of disease severity. Well-controlled baseline low-density lipoprotein cholesterol was associated with a reduced likelihood of angiography. These findings point to the importance of a comprehensive assessment of symptoms and a review of guideline-directed medical therapy goals when deciding the initial treatment strategy for chronic coronary disease. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT01471522.

Successful Treatment of Confirmed Severe Bupropion Cardiotoxicity With Veno-Arterial Extracorporeal Membrane Oxygenation Initiation Prior to Cardiac Arrest.

Bupropion is a substituted cathinone (ß-keto amphetamine) norepinephrine/dopamine reuptake inhibitor andnoncompetitive nicotinic acetylcholine receptor antagonist that is frequently used to treat major depressive disorder. Bupropion overdose can cause neurotoxicity and cardiotoxicity, the latter of which is thought to be secondary to gap junction inhibition and ion channel blockade. We report a patient with a confirmed bupropion ingestion causing severe cardiotoxicity, for whom prophylactic veno-arterial extracorporeal membrane oxygenation (ECMO) was successfully implemented. The patient was placed on the ECMO circuit several hours before he experienced multiple episodes of hemodynamically unstable ventricular tachycardia, which were treated with multiple rounds of electrical defibrillation and terminated after administration of lidocaine. Despite a neurological examination notable for fixed and dilated pupils after ECMO cannulation, the patient completely recovered without neurological deficits. Multiple bupropion and hydroxybupropion concentrations were obtained and appear to correlate with electrocardiogram interval widening and toxicity.

Relationship between the mixed venous-to-arterial carbon dioxide gradient and the cardiac index in acute pulmonary embolism.

AIMS: Among patients with acute pulmonary embolism (PE) undergoing mechanical thrombectomy, the cardiac index (CI) is frequently reduced even among those without a clinically apparent shock. The purpose of this study is to describe the mixed venous-to-arterial carbon dioxide gradient (CO2 gap), a surrogate of perfusion adequacy, among patients with acute PE undergoing mechanical thrombectomy. METHODS AND RESULTS: This was a single-centre retrospective study of consecutive patients with PE undergoing mechanical thrombectomy and simultaneous pulmonary artery catheterization over a 3-year period. Of 107 patients, 97 had simultaneous mixed venous and arterial blood gas measurements available. The CO2 gap was elevated (>6 mmHg) in 51% of the cohort and in 49% of patients with intermediate-risk PE. A reduced CI (≤2.2 L/min/m2) was associated with an increased odds [odds ratio = 7.9; 95% confidence interval (CI) 3.49-18.1, P < 0.001] for an elevated CO2 gap. There was an inverse relationship between the CI and the CO2 gap. For every 1 L/min/m2 decrease in the CI, the CO2 gap increased by 1.3 mmHg (P = 0.001). Among patients with an elevated baseline CO2 gap >6 mmHg, thrombectomy improved the CO2 gap, CI, and mixed venous oxygen saturation. When the CO2 gap was dichotomized above and below 6, there was no difference in the in-hospital mortality rate (9 vs. 0%; P = 0.10; hazard ratio: 1.24; 95% CI 0.97-1.60; P = 0.085). CONCLUSION: Among patients with acute PE undergoing mechanical thrombectomy, the CO2 gap is abnormal in nearly 50% of patients and inversely related to the CI. Further studies should examine the relationship between markers of perfusion and outcomes in this population to refine risk stratification.