Systematic review of electrophysiology procedures in patients with obstruction of the inferior vena cava.

AIMS: The objective of the study was to conduct a systematic review to describe and compare the different approaches for performing cardiac electrophysiology (EP) procedures in patients with interrupted inferior vena cava (IVC) or equivalent entities causing IVC obstruction. METHODS: We conducted a structured search to identify manuscripts reporting EP procedures with interrupted IVC or IVC obstruction of any aetiology published up until August 2020. No restrictions were applied in the search strategy. We also included seven local cases that met inclusion criteria. RESULTS: The analysis included 142 patients (mean age 48.9 years; 48% female) undergoing 143 procedures. Obstruction of the IVC was not known before the index procedure in 54% of patients. Congenital interruption of IVC was the most frequent cause (80%); and, associated congenital heart disease (CHD) was observed in 43% of patients in this setting. The superior approach for ablation was the most frequently used strategy (52%), followed by inferior approach via the azygos or hemiazygos vein (24%), transhepatic approach (14%), and retroaortic approach (10%). Electroanatomical mapping (58%), use of long sheaths (41%), intracardiac echocardiography (19%), transesophageal echocardiography (15%) and remote controlled magnetic navigation (13%) were used as adjuncts to aid performance. Ablation was successful in 135 of 140 procedures in which outcomes were reported. Major complications were only reported in patients undergoing AF ablation, including two patients with pericardial effusion, one of whom required surgical repair, and another patient who died after inadvertent entry into an undiagnosed atrioesophageal fistula from a previous procedure. CONCLUSION: The superior approach is most frequent approach for performing EP procedures in the setting of obstructed IVC. Transhepatic approach is a feasible alternative, and may provide a "familiar approach" for transseptal access when it is required. Adjunctive use of long sheaths, intravascular echocardiography, electro-anatomical mapping and remote magnetic navigation may be helpful, especially if there is associated complex CHD. With careful planning, EP procedures can usually be successfully performed with a low risk of complications.

Comparison of Multiplate and VerifyNow platelet function tests in predicting clinical outcome in patients with acute coronary syndromes.

INTRODUCTION: This study examined the ability of two widely used "point of care" platelet function assays, VerifyNow and Multiplate, to predict adverse outcomes in patients with acute coronary syndromes (ACS). METHODS: We examined platelet reactivity using VerifyNow and Multiplate P2Y12 assays in patients with ACS and the relationship between platelet reactivity and both MACE (defined as a composite of death, myocardial infarction, stroke, stent thrombosis and unplanned revascularisation) and TIMI major bleeding at 1year. RESULTS: In 619 ACS patients, 65 patients (10.5%) had experienced MACE at 1year and 6 patients (1%) had TIMI major bleeding events. The two measures of platelet reactivity were only moderately correlated (Rho=0.43, p=0.0001). Both measures demonstrated a statistically significant relationship with MACE, with area under the curve for VerifyNow of 0.632 (0.001) and for Multiplate of 0.577 (p=0.04), and neither measure showed a significant relationship with bleeding. Logistic regression analysis found that only VerifyNow was a statistical predictor of MACE (p=0.01). MACE occurred in 16% of those classified as having HPR using VerifyNow compared to 7% in those without HPR (odds ratio of 2.6 (95% CI 1.5-4.4, p=0.001). In those classified as having HPR by the Multiplate assay, MACE occurred in 13% compared to 9% of those without HPR (Odds ratio 1.5 95% CI 0.9-2.5, p=0.11). CONCLUSION: The two points of care platelet function tests examined in this study were only moderately correlated. The VerifyNow assay demonstrated a stronger relationship to MACE than the Multiplate assay.

Differing Clinical Characteristics Between Young and Older Patients Presenting with Myocardial Infarction.

BACKGROUND: To date, there has been no detailed study of the risk factors and clinical characteristics of patients presenting with myocardial infarction (MI) at a young age in our region. The purpose of this study was to assess the rate and clinical profile of those presenting with young MI in New Zealand. METHODS: We identified a cohort of 1199 patients presenting with acute MI between January 2012 and November 2015 from the Wellington Acute Coronary Syndrome Registry. We compared those presenting with young MI, defined as presentation with MI aged 50 years or younger, to those aged over 50 years. RESULTS: Myocardial infarction at a young age occurred in 154 (12.8%) patients. Compared to those in the older MI group, the young MI group were more likely to be male (80% vs. 71%, p=0.026), of Maori or Pacific Island ethnicity (21% vs. 10%, p<0.0001), have a higher BMI (31kg/m2 vs. 29kg/m2, p<0.0001), have a family history of premature coronary artery disease (49% vs. 34%, p<0.0001) and to be current smokers (47% vs. 20%, p<0.001). Young MI patients were less likely to have hypertension, dyslipidaemia and diabetes than the older MI patient population. Within the young MI group 36% had none or only one traditional risk factor for MI, and would have been classified as low risk prior to their index event. CONCLUSION: Those with young MI accounted for 12.8% of our cohort and had a different risk factor profile to the older MI group with smoking and obesity being particularly prevalent.