Intravascular Ultrasound-Guided versus Angiography-Guided Percutaneous Coronary Intervention for Stent Thrombosis Elevation Myocardial Infarction: An Updated Systematic Review and Meta-Analysis.

INTRODUCTION: Intravascular ultrasound (IVUS) provides intra-procedural guidance in optimizing percutaneous coronary interventions (PCI) and has been shown to improve clinical outcomes in stent implantation. However, current data on the benefit of IVUS during PCI in ST-elevation myocardial infarction (STEMI) patients is mixed. We performed meta-analysis pooling available data assessing IVUS-guided versus angiography-guided PCI in STEMI patients. METHODS: We conducted a systematic search on PubMed and Embase for studies comparing IVUS versus angiography-guided PCI in STEMI. Mantel-Haenszel random effects model was used to calculate risk ratios (RRs) with 95% confidence intervals (CIs) for outcomes of major adverse cardiovascular events (MACEs), death, myocardial infarction (MI), target vessel revascularization (TVR), stent thrombosis (ST) and in-hospital mortality. RESULTS: A total of 8 studies including 336,649 individuals presenting with STEMI were included for the meta-analysis. Follow-up ranged from 11 to 60 months. We found significant association between IVUS-guided PCI with lower risk for MACE (RR 0.82, 95% CI 0.76-0.90) compared with angiography-guided PCI. We also found significant association between IVUS-guided PCI with lower risk for death, MI, TVR, and in-hospital mortality but not ST. CONCLUSION: In our meta-analysis, IVUS-guided compared with angiography-guided PCI was associated with improved long-term and short-term clinical outcomes in STEMI patients.

Long-Term Ambulatory Intravenous Milrinone Therapy in Advanced Heart Failure.

BACKGROUND: The role of intravenous (IV) inotropes in the treatment of ambulatory patients with advanced heart failure (HF) remains controversial. METHODS: This was a retrospective study of patients with advanced HF. Patients on home IV milrinone, who remained on it for at least 3 months, were included. We compared the data from 3 months before starting IV milrinone to 3 months after initiating therapy. A subset of patients who remained on milrinone for 6 months or longer was analysed separately. RESULTS: A total of 90 patients remained on continuous IV milrinone for 3 months, and 55 patients were treated for 6 months or longer. In both groups, improvements in cardiac index (1.86-2.25, p<0.001 and 1.9-2.38, p<0.0001), New York Heart Association (NYHA) class (3.32-2.76, p<0.0001 and 3.25-2.72, p=0.001), and liver function were noted. In the 6-month group, there was also a decrease in mean hospitalised days per patient (9.40 vs 4.12, p<0.001) and an improved tolerance of beta blocker therapy (83.3% vs 98.1%, p=0.006). CONCLUSION: Long-term IV use of milrinone is associated with improvement in haemodynamics, functional class, tolerance of medical therapy, and decrease in hospitalised days.

Impact of Elevated Gradients After Transcatheter Aortic Valve Implantation for Degenerated Surgical Aortic Valve Bioprostheses.

BACKGROUND: Elevated aortic valve gradients are common after transcatheter aortic valve implantation for degenerated surgical aortic valve replacement bioprostheses, but their clinical impact is uncertain. METHODS: A total of 12 122 patients who underwent transcatheter aortic valve implantation-in-surgical aortic valve replacement from November 2011 to December 2019 in the Society of Thoracic Surgery/American College of Cardiology Transvalvular Therapeutics Registry were included. The primary outcome was a composite of 1-year all-cause mortality, stroke, myocardial infarction, or valve reintervention. Secondary outcomes included 1-year all-cause mortality, readmission, and change from baseline 12-question self-administered Kansas City Cardiomyopathy Questionnaire-Overall Summary Score. Due to nonlinearity observed with restricted cubic splines analysis, a Cox regression analysis with aortic valve mean gradient modeled as a spline-continuous variable (with 20 mm Hg as a cutoff) was used to study the 1-year composite outcome and mortality. RESULTS: The composite outcome occurred most frequently in patients with aortic valve mean gradient ≥30 and <10 mm Hg, as compared with those with 10 to 20 and 20 to 30 mm Hg ranges (unadjusted rates, 13.9%, 12.1%, 7.5%, and 6.5%, respectively; P=0.002). When the mean aortic valve gradient was ≥20 mm Hg, higher gradients were associated with greater risk of the 1-year composite outcome (adjusted hazard ratio, 1.02 [1.02-1.03] per mm Hg; P<0.001) and 1-year mortality (adjusted hazard ratio, 1.02 [1.00-1.03] per mm Hg; P=0.007). Whereas when the mean aortic valve gradient was <20 mm Hg, higher gradients were not significantly associated with the composite outcome (adjusted hazard ratio, 0.99 [0.98-1.003] per mm Hg; P=0.12) but were associated with lower 1-year mortality (adjusted hazard ratio, 0.98 [0.97-0.99] per mm Hg; P=0.007). CONCLUSIONS: The relationship between postprocedural aortic valve mean gradient after transcatheter aortic valve implantation-in-surgical aortic valve replacement and clinical outcomes is complex and nonlinear, with relatively greater adverse events occurring at low and high gradient extremes. Further study of factors mediating the relationship between postprocedural gradients and clinical outcomes, including low-flow states, is necessary.

Flecainide Toxicity Resulting in Pacemaker Latency and Intermittent Failure to Capture.

BACKGROUND Flecainide is a class Ic antiarrhythmic agent used in the treatment of supraventricular and ventricular arrhythmias. It is associated with a potent adverse effect profile; however, the effects of flecainide toxicity in the setting of a pacemaker have not been well described. We describe a unique case of flecainide toxicity secondary to acute kidney injury in the setting of a dual-chamber pacemaker, resulting in ventricular capture latency and intermittent failure to capture. CASE REPORT The patient was a 91-year-old female with a history of atrial fibrillation maintained in sinus rhythm on flecainide, who presented complaining of purple visual disturbances and syncope. She was found to be hypotensive and bradycardic, with a heart rate between 30 to 40 beats per minute. Lab work was notable for creatinine at 2.12 mg/dL. A 12-lead ECG demonstrated atrial and ventricular pacing with severely widened QRS complex and a significant latency between the pacemaker ventricular spike and the ventricular capture. The pacemaker was interrogated, revealing a significant increase in ventricular threshold from 0.75 V at 0.5 ms at baseline to 5.0 V at 1 ms to obtain consistent capture. After multiple boluses of IV sodium bicarbonate, the QRS acutely narrowed, latency interval improved, and consistent pacing capture was achieved. The flecainide level drawn on arrival was 3.09 mcg/mL. CONCLUSIONS Flecainide increases the ventricular capture threshold for pacemakers. Toxicity in these patients may present with pacemaker ventricular capture latency or failure to capture.

Fluctuations in premature ventricular contraction burden can affect medical assessment and management.

BACKGROUND: Frequent premature ventricular contractions (PVCs) can cause disabling symptoms and decrease left ventricular ejection fraction. PVC burden, typically quantified by a 24-hour monitor, is one of the factors that determines the clinical management of PVCs. OBJECTIVE: The purpose of this study was to evaluate the extent of variability in 24-hour PVC burden during 14-day ambulatory cardiac monitoring in patients with significant PVC burden. METHODS: All patients referred for PVC evaluation received a 14-day ambulatory cardiac monitor. Parameters of interest included mean 14-day PVC burden, minimum and maximum 24-hour PVC burden, and absolute change in 24-hour PVC burden (maximum minus minimum). We included only patients with a mean 14-day PVC burden of more than 5%. RESULTS: Fifty-nine patients were included in the study. The median of mean 14-day PVC burden, maximum 24-hour PVC burden, and minimum 24-hour PVC burden were 9.0% (IQR 6.4%-17.9%), 16.2% (IQR 11.7%-26.2%), and 4.5% (IQR 2.6%-11.2%) respectively (P < .001). The median of the absolute 24-hour PVC burden change was 9.9% (IQR 5.4%-14.5%). There was a 2.45-fold (IQR 1.68- to 5.55-fold) median difference between maximum 24-hour PVC burden and minimum 24-hour burden in the same patient. When categorized by low (<10%), intermediate (10%-20%), and high (>20%) 24-hour PVC burden, 72.9% patients fell into at least 2 categories depending on the 24-hour period considered. CONCLUSION: There is a significant variation in 24-hour PVC burden when measured over a 14-day period in patients with of PVC burden of more than 5%. This variation might impact critical clinical decisions in a significant proportion of such patients.

Comparison of Complications of Catheter Ablation for Ventricular Arrhythmias in Adults With Versus Without Structural Heart Disease.

Catheter ablation (CA) is an effective treatment for ventricular arrhythmias (VA), with a potential for complications. The presence of structural heart disease (SHD) is associated with a higher complication rate although there is no data comparing CA of VA between patients with SHD and those without. We aimed to compare trends, morbidity, and mortality associated with real world practice of CA for VA (ventricular tachycardia and premature ventricular contraction) based on the presence of SHD. Using weighted sampling in the National Inpatient Sample database, we collected and compared characteristics and outcomes of patients with or without SHD that underwent CA of VA. Among 34,907 patients that underwent CA for VA (1999-2013), 18,014 (51.6%) had SHD. Major and all complications occurred among 1,135/18,014 (6.3%) and 2139/18,014 (11.9%) patients with SHD respectively compared with 355/16,893 (2.1%) and 739/16,893 (4.4%) for patients without SHD, p < 0.001 for both comparisons. Furthermore, 452/18,014 (2.51%) with SHD died versus 20/16,893 (0.12%) without SHD, p < 0.001. Heart failure was associated with an odds ratio (OR) of 3.09 for major complications (95%CI: 1.53-6.27, p = 0.002) for patients with SHD while coronary artery disease OR for major complications was 2.47 (95%CI: 1.44-4.23, p = 0.001) for patients without SHD. There was a significant increase in major complications over the 15-year study period in patients with SHD, p < 0.001. In conclusion, the presence of SHD during CA for VA increased the complication rate of major and any complications by approximately threefold for both and the hospital mortality by >20-fold compared with patients without SHD.

Sex differences in complications of catheter ablation for atrial fibrillation: results on 85,977 patients.

PURPOSE: Catheter ablation (CA) is an effective treatment for atrial fibrillation (AF). The differences in complication rates and outcomes between women and men remain poorly studied. We aimed to study the sex differences in morbidity and mortality associated with CA in AF. METHODS: Using weighted sampling from the National Inpatient Sample database, women and men with a primary diagnosis of AF and a primary procedure of CA (2004-2013) were identified. We compared the following outcomes based on the sex: (1) major complications [post-procedure transfusion, cardiac drain or surgery, pulmonary embolism, cerebrovascular accident, major cardiac events, kidney failure requiring dialysis, and sepsis], (2) overall complications (minor and/or major complications), and (3) in-hospital mortality. RESULTS: Among 85,977 patients who underwent CA for AF, 27821 (32.4%) were women. Overall complications were more frequent among women versus among men (12.4% versus 9.0%; p < 0.001), as well as major complications (4.7% versus 2.7%; p < 0.001). However, there was no difference in mortality (0.3% versus 0.2%; p = 0.22). After adjusting for other factors, women were more likely than men to have major complication (odds ratio 1.48, 95% CI 1.21-1.82; p < 0.001). Prior CABG was associated with lower risk of major complications in both sexes (odds ratio in the overall cohort 0.27, 95% CI 0.12-0.61; p = 0.002), mostly driven by the reduction in tamponade and pericardial drain. CONCLUSIONS: Among patients who underwent catheter ablation for AF, the female sex was associated with higher rate of complications compared to male but no difference in mortality. Prior CABG was associated with a significant reduction of major complications in both sexes.