Emergency out-of-hours catheter ablation for ventricular arrhythmia storm: a UK and Australian experience.

AIMS: There are limited data on emergency catheter ablation (CA) for ventricular arrhythmia (VA) storm. We describe the feasibility and safety of performing emergency CA in an out-of-hours setting for VA storm refractory to medical therapy at 2 tertiary hospitals. METHODS AND RESULTS: Twenty-five consecutive patients underwent out-of-hours (5pm-8am [weekday] or Friday 5pm-Monday 8am [weekend]) CA for VA storm refractory to anti-arrhythmic drugs and sedation. Baseline and procedural characteristics along with outcomes were compared to 91 consecutive patients undergoing weekday daytime-hours (8am-5pm) CA for VA storm. More patients undergoing out-of-hours CA had a left ventricular ejection fraction ≤35% (68% vs. 42%, P = 0.022), chronic kidney disease (60% vs. 20%, P < 0.001), and presented following a resuscitated out-of-hospital cardiac arrest (56% vs. 5%, P < 0.001), compared to the daytime-hours group. During median follow-up (377 [interquartile range 138-826] days), both groups experienced similar survival free from recurrent VA and VA storm. Survival free from cardiac transplant and/or mortality was lower in the out-of-hours group (44% vs. 81%, P = 0.007), but out-of-hours CA was not independently associated with increased cardiac transplant and/or mortality (hazard ratio 1.34, 95% confidence interval 0.61-2.96, P = 0.47). Of the 11 patients in the out-of-hours group who survived follow-up, VA-free survival was 91% and VA storm-free survival was 100% at 1-year after CA. CONCLUSION: Out-of-hours CA may occasionally be required to control VA storm and can be safe and efficacious in this scenario. During follow-up, cardiac transplant and/or mortality is common but undergoing out-of-hours CA was not predictive of this composite endpoint.

Predicting Patients With Troponin Positive Chest Pain and Unobstructed Coronary Arteries With Electrocardiogram, Troponin Kinetics and GRACE Score.

BACKGROUND: Troponin positive chest-pain with unobstructed coronary arteries (TPCP-UCA), occurs in 6% of cases of patients presenting with acute coronary syndrome (ACS). Whilst TPCP-UCA patients are known to be younger with less cardiovascular risk factors when compared to obstructive coronary disease (MICAD), no validated methods exist to reliably delineate these two conditions prior to coronary angiography. METHODS: We analysed 142 patients with MICAD and 127 patients with TPCP-UCA from 2015 to 2019. Several key predetermined clinical, biochemical and electrocardiograph (ECG) parameters, as well as Global Registry of Acute Coronary Events (GRACE) score, were collected for all patients. All TPCP-UCA patients underwent cardiac magnetic resonance imaging (cMRI). RESULTS: Patients with TPCP-UCA were younger than MICAD (44 vs 68 yrs, p<0.01), and with less cardiac risk factors of hypertension (31% vs 68%, p<0.01), hypercholesterolaemia (23% vs 56%, p<0.01), diabetes (11% vs 45%, p<0.01), prior ischaemic heart disease (8% vs 42%, p<0.01) and smoking history (29% vs 50%, p<0.01). Peak troponin (MICAD 2,084.5 ng/L vs TPCP-UCA 847.0 ng/L, p=0.02), serial-to-initial troponin ratio (MICAD 13.5 vs TPCP-UCA 5.1, p<0.01), and peak-to-initial troponin ratio (MICAD 69.6 vs TPCP-UCA 14.0, p<0.01) were all higher in the MICAD group. GRACE scores were significantly different across the two cohorts (TPCP UCA 74 vs MICAD 106, p<0.01), with a receiver operator characteristic (ROC) curve statistic of 0.794 (95% CI 0.739-0.850). On ECG analysis, MICAD had greater prevalence and sum of ST depression (40% vs 19% p<0.01; 1.6 mm vs 0.44 mm, p<0.01) and T wave inversion (37% vs 17%, p<0.01), whilst TPCP-UCA had greater presence of PR depression (20% vs 3% p<0.01), and longer repolarisation (T wave peak to end 89 ms vs 83 ms, p=0.04; T wave peak to end/corrected QT 0.208 ms vs 0.193 ms, p=0.03). All TPCP-UCA patients underwent cMRI. Aetiology was found in 82% of cases, with the leading diagnosis being myocarditis (58%), followed by infarction (8%), whilst 18% had a normal cMRI. CONCLUSIONS: TPCP-UCA is an important differential for patients presenting with ACS, and has several key demographic, biochemical and electrocardiographic differences. The present findings are hypothesis generating, thus prospective studies are required to determine and validate potential clinical utility.

Lockdown Without Loss? A Natural Experiment of Net Payoffs from COVID-19 Lockdowns.

Lacking a federal policy to control the spread of COVID-19, state governors ordered lockdowns and mask mandates, at different times, generating a massive natural experiment. The authors exploit this natural experiment to address four issues: (1) Were lockdowns effective in reducing infections? (2) What were the costs to consumers? (3) Did lockdowns increase (signaling effect) or reduce (substitution effect) consumers' mask adoption? (4) Did governors' decisions depend on medical science or nonmedical drivers? Analyses via difference-in-differences and generalized synthetic control methods indicate that lockdowns causally reduced infections. Although lockdowns reduced infections by 480 per million consumers per day (equivalent to a reduction of 56%), they reduced customer satisfaction by 2.2%, consumer spending by 7.5%, and gross domestic product by 5.4% and significantly increased unemployment by 2% per average state by the end of the observation period. A counterfactual analysis shows that a nationwide lockdown on March 15, 2020, would have reduced total cases by 60%, whereas the absence of any state lockdowns would have resulted in five times more cases by April 30. The average cost of reducing the number of cases by one new infection was about $28,000 in lower gross domestic product.

Remote magnetic navigation compared to contemporary manual techniques for the catheter ablation of ventricular arrhythmias in structural heart disease.

BACKGROUND: There are limited data comparing remote magnetic navigation (RMN) to contemporary techniques of manual-guided ventricular arrhythmia (VA) catheter ablation. OBJECTIVES: We compared acute and long-term outcomes of VA ablation guided by either RMN or contemporary manual techniques in patients with structural heart disease. METHODS: From 2010-2019, 192 consecutive patients, with ischemic cardiomyopathy (ICM) or non-ischemic cardiomyopathy (NICM) underwent catheter ablation for sustained ventricular tachycardia (VT) or premature ventricular complexes (PVCs), using either RMN (n = 60) or manual (n = 132) guided techniques. Acute success and VA-free survival were compared. RESULTS: In ICM, acute procedural success was comparable between the 2 techniques (manual 43.5% vs. RMN 29%, P = 0.11), as was VA-free survival (manual 83% vs. RMN 74%, P = 0.88), and survival free from cardiac transplantation and all-cause mortality (manual 88% vs. RMN 87%, P = 0.47), both at 12-months after final ablation. In NICM, manual compared to RMN guided, had superior acute procedural success (manual 46% vs. RMN 19%, P = 0.003) and VA-free survival 12-months after final ablation (manual 79% vs. RMN 41%, P = 0.004), but comparable survival free from cardiac transplantation and all-cause mortality 12-months after final ablation (manual 95% vs. RMN 90%, P = 0.52). Procedural duration was shorter in both subgroups undergoing manual guided ablation, whereas fluoroscopy dose and complication rates were comparable. CONCLUSION: RMN provides similar outcomes to manual ablation in patients with ICM. In NICM however, acute success, and long-term VA-free survival was better with manual ablation. Prospective, multi-centre randomised trials comparing contemporary manual and RMN systems for VA catheter ablation are needed.

Nodal metastasis size predicts disease-free survival in cutaneous head and neck squamous cell carcinoma involving the parotid but not cervical nodes.

BACKGROUND: The 8th edition American Joint Committee on Cancer nodal (N) staging of cutaneous squamous cell carcinoma of the head and neck (cSCCHN) is largely based on lymph node metastasis size, despite conflicting data in the literature. This study aimed to investigate the prognostic significance of largest node size in cSCCHN. METHODS: Retrospective analysis of 94 patients undergoing curative-intent treatment for nodal cSCCHN with surgery ± radiotherapy at Liverpool Hospital, Sydney, Australia was conducted. Survival outcomes were assessed using multivariate Cox regression. The primary end point was disease-free survival (DFS). Objective measures of model performance were used in exploratory analyses to identify optimal size thresholds for predicting survival. RESULTS: Nodal metastasis size significantly predicted DFS on multivariate analysis (hazard ratio 1.24; 95% confidence interval 1.06-1.46; P = 0.008). This prognostic impact occurred predominantly in parotid metastases (hazard ratio 1.27; 95% confidence interval 1.07-1.51; P = 0.006); each 1 cm increase in size increased the risk of recurrence or death by 27%, irrespective of the number of involved nodes. In parotid metastases, size thresholds of ≤3, 3-4.5 and >4.5 cm optimized prognostic discrimination. Extranodal extension (ENE) was associated with decreased DFS in nodes ≤3 cm in size (P = 0.025), but not in those >3 cm (P = 0.744). CONCLUSION: Size is an important prognostic factor in cSCCHN with parotid metastases, with optimal thresholds of ≤3, >3-4.5 and >4.5 cm. The prognostic impact of ENE was seen only in nodal metastases ≤3 cm in size. These results may have important implications for node size thresholds and inclusion of ENE in the American Joint Committee on Cancer N staging categories.

A critical analysis of the prognostic performance of the 8th edition American Joint Committee on Cancer staging for metastatic cutaneous squamous cell carcinoma of the head and neck.

BACKGROUND: The 8th edition AJCC staging of cutaneous squamous cell carcinoma of the head and neck (cSCCHN) incorporated extranodal extension (ENE) for the first time. This study compared the prognostic performance of the 7th and 8th edition staging for cSCCHN with nodal metastases. METHODS: Retrospective analysis of 96 patients with metastatic cSCCHN, comparing the ability of staging systems to predict disease-specific and overall survival (OS) using the proportion of variation explained and Harrell's C-index. RESULTS: In AJCC8, the N classification was upstaged in 77% of patients due to the presence of ENE and 88% of patients were classified as TNM stage IV. AJCC8 was inferior to AJCC7 in predicting disease-specific survival for both N and TNM stages, and OS by TNM stage. CONCLUSIONS: The majority of patients with metastatic cSCCHN have ENE and are classified as TNM stage IV based on the 8th edition staging, resulting in poor prognostic performance.

Number of nodal metastases and prognosis in metastatic cutaneous squamous cell carcinoma of the head and neck.

BACKGROUND: Existing prognostic systems for metastatic cutaneous squamous cell carcinoma of the head and neck (cSCCHN) do not discriminate between the number of involved nodes beyond single versus multiple. This study aimed to determine if the number of metastatic lymph nodes is an independent prognostic factor in metastatic cSCCHN and whether it provides additional prognostic information to the American Joint Committee on Cancer (AJCC) staging. METHODS: We retrospectively analysed 101 patients undergoing curative intent treatment for metastatic cSCCHN to parotid and/or neck nodes by surgery +/- radiotherapy at Liverpool Hospital, Sydney, Australia. The impact of number of nodal metastases on disease-free survival (DFS) and risk of distant metastases was assessed using multivariate Cox regression. RESULTS: The mean number of nodal metastases was 2.5 (range 1-12). On multivariate analysis, increasing number of nodal metastases significantly predicted reduced DFS (hazard ratio 1.17; 95% confidence interval 1.05-1.30; P = 0.004), with a 17% increased risk of recurrence or death for each additional node. This remained significant in multivariate models adjusted for AJCC 8th edition nodal and TNM stages. Number of nodal metastases was also associated with risk of distant metastatic failure (hazard ratio 1.21; 95% confidence interval 1.05-1.39; P = 0.009). CONCLUSION: Increasing number of nodal metastases is associated with decreased DFS and increased risk of distant metastases in metastatic cSCCHN, with a cumulative risk increase with each additional node. It provides additional prognostic information to the AJCC staging, which may be improved by incorporating information on the number of nodal metastases beyond the current single versus multiple distinction.