Clinical Protocol for Selecting Intracardiac or Transesophageal Echocardiography-Guided Left Atrial Appendage Occlusion.

Intracardiac echocardiography (ICE) has emerged as an alternative to transesophageal echo (TEE) to guide left atrial appendage occlusion (LAAO). We established a protocol to select patients appropriate for ICE guidance. Patients who underwent LAAO with the Watchman or Watchman FLX device (Boston Scientific, Marlborough, Massachusetts) from January 2018 to March 2022 at a large United States center were included. The novel protocol prospectively selected TEE or ICE guidance beginning in January 2020; previous LAAO procedures were retrospectively included. ICE was selected for patients with uninterrupted anticoagulation and appropriate LAA anatomy, renal function, and moderate sedation tolerance. In-hospital outcomes with successful implantation without conversion to TEE guidance, no peridevice leak, and no procedural complications were compared. Composite 1-year outcome included freedom from peridevice leak, device-related thrombus, stroke, and all-cause mortality. A total of 234 patients were included; the mean age was 76.1 ± 8.3 years old, and 42.3% were female. ICE guidance was used for 63 procedures; TEE guidance was used for 171 procedures. For the composite outcome, ICE-guided LAAO was superior to TEE-guided LAAO (risk difference 0.102, 96.8% vs 86.5%, 95% confidence interval 0.003 to 0.203, p = 0.029). In comparison to the TEE-guided group, ICE-guided procedures were shorter (89.1 ± 26.3 vs 99.8 ± 30.0 min, p = 0.0087) with less general anesthesia (26.6% vs 98.8%, p <0.0001). One-year composite adverse outcomes did not differ significantly (80.7% vs 88.9%, p = 0.17). In conclusion, the protocol to select appropriate patients for ICE versus TEE guidance for LAAO is safe and effective. Larger studies are indicated to validate this approach to improve outcomes, shorten procedures, and avoid general anesthesia.

HIV-Tat Exacerbates the Actions of Atazanavir, Efavirenz, and Ritonavir on Cardiac Ryanodine Receptor (RyR2).

The incidence of sudden cardiac death (SCD) in people living with HIV infection (PLWH), especially those with inadequate viral suppression, is high and the reasons for this remain incompletely characterized. The timely opening and closing of type 2 ryanodine receptor (RyR2) is critical for ensuring rhythmic cardiac contraction-relaxation cycles, and the disruption of these processes can elicit Ca2+ waves, ventricular arrhythmias, and SCD. Herein, we show that the HIV protein Tat (HIV-Tat: 0-52 ng/mL) and therapeutic levels of the antiretroviral drugs atazanavir (ATV: 0-25,344 ng/mL), efavirenz (EFV: 0-11,376 ng/mL), and ritonavir (RTV: 0-25,956 ng/mL) bind to and modulate the opening and closing of RyR2. Abacavir (0-14,315 ng/mL), bictegravir (0-22,469 ng/mL), Rilpivirine (0-14,360 ng/mL), and tenofovir disoproxil fumarate (0-18,321 ng/mL) did not alter [3H]ryanodine binding to RyR2. Pretreating RyR2 with low HIV-Tat (14 ng/mL) potentiated the abilities of ATV and RTV to bind to open RyR2 and enhanced their ability to bind to EFV to close RyR2. In silico molecular docking using a Schrodinger Prime protein-protein docking algorithm identified three thermodynamically favored interacting sites for HIV-Tat on RyR2. The most favored site resides between amino acids (AA) 1702-1963; the second favored site resides between AA 467-1465, and the third site resides between AA 201-1816. Collectively, these new data show that HIV-Tat, ATV, EFV, and RTV can bind to and modulate the activity of RyR2 and that HIV-Tat can exacerbate the actions of ATV, EFV, and RTV on RyR2. Whether the modulation of RyR2 by these agents increases the risk of arrhythmias and SCD remains to be explored.

Clinical Decision-Making for the Hemodynamic "Gray Zone" (FFR 0.75-0.80) and Long-Term Outcomes.

BACKGROUND: Fractional flow reserve (FFR) value between 0.75 and 0.80 is considered the "gray zone" and outcomes data relative to treatment strategy (revascularization vs medical therapy alone [deferral]) are limited for this group. METHODS AND RESULTS: A total of 238 patients (64.3 ± 8.6 years; 97% male; 45% diabetic) with gray-zone FFR were followed for the primary endpoint of major adverse cardiovascular event (MACE), defined as a composite of death, myocardial infarction (MI), and target-vessel revascularization. Mean follow-up duration was 30 ± 17 months. Deferred patients (n = 48 [20%]) had a higher prevalence of smoking and chronic kidney disease compared with the percutaneous coronary intervention (PCI) group (n = 190 [80%]; P<.05). Patients who underwent PCI had significantly lower MACE compared with the deferred patients (16% vs 40%; log rank P<.01). While there was a trend toward a decrease in all-cause mortality (8% vs 19%; log rank P=.06), the composite of death or MI was significantly lower in the PCI group (9% vs 27%; P<.01). On multivariate Cox proportional hazards regression analysis, PCI was associated with lower MACE (hazard ratio, 0.5; 95% confidence interval, 0.27-0.95; P=.03). CONCLUSION: Revascularization for patients with gray-zone FFR was associated with a significantly reduced risk of MACE compared with medical therapy alone.