COVID-19 Pandemic Impact on Percutaneous Coronary Intervention for Acute Coronary Syndromes: An Australian Tertiary Centre Experience.

BACKGROUND: Countries who suffered large COVID-19 outbreaks reported a decrease in acute coronary syndrome (ACS) presentations and percutaneous coronary intervention (PCI). The impact of the pandemic in countries like Australia, with relatively small outbreaks yet significant social restrictions, is relatively unknown. There is also limited and conflicting data regarding the impact on clinical outcomes, symptom-to-door time (STDT) and door-to-balloon time (DTBT). METHODS: Consecutive ACS patients treated with PCI were prospectively recruited from a tertiary hospital network in Melbourne, Australia. The pre-pandemic period (11 March 2019-10 March 2020) was compared to the pandemic period (11 March 2020-10 May 2020) using an interrupted time series analysis with a primary endpoint of number PCI-treated ACS per day. Secondary endpoints included STDT, DTBT, total mortality and major adverse cardiac events (MACE). RESULTS: A total 984 ACS patients (14.8% during the pandemic period) received PCI. Mean number of PCI-treated ACS per day did not differ between the two periods (2.3 vs 2.4, p=0.61) with no difference in STDT [+51.3 mins, 95% confidence interval (CI) -52.4 to 154.9, p=0.33], 30-day mortality (5% vs 5.3%, p=0.86) or MACE (5.2% vs 6.1%, p=0.68). DTBT was significantly longer during the pandemic versus the pre-pandemic period (+18.1 mins, 95% CI 1.6-34.5, p=0.03) and improved with time (slope estimate: -0.76, 95% CI -1.62 to 0.10). CONCLUSIONS: Despite significant social restrictions imposed in Melbourne, numbers of ACS treated with PCI and 30-day outcomes were similar to pre-pandemic times. DTBT was significantly longer during the COVID-19 pandemic period, likely reflecting infection control measures, which reassuringly improved with time.

Non-hyperaemic pressure ratios to guide percutaneous coronary intervention.

The use of fractional flow reserve (FFR) in guiding revascularisation improves patient outcomes and has been well-established in clinical guidelines. Despite this, the uptake of FFR has been limited, likely attributable to the perceived increase in procedural time and use of hyperaemic agents that can cause patient discomfort. This has led to the development of instantaneous wave-free ratio (iFR), an alternative non-hyperaemic pressure ratio (NHPR). Since its inception, the use of iFR has been supported by an increasing body of evidence and is now guideline recommended. More recently, other commercially available NHPRs including diastolic hyperaemia-free ratio and resting full-cycle ratio have emerged. Studies have demonstrated that these indices, in addition to mean distal coronary artery pressure to mean aortic pressure ratio, are mathematically analogous (with specific nuances) to iFR. Additionally, there is increasing data demonstrating the equivalent diagnostic performance of alternative NHPRs in comparison with iFR and FFR. These NHPRs are now integral within most current pressure wire systems and are commonly available in the catheter laboratory. It is therefore key to understand the fundamental differences and evidence for NHPRs to guide appropriate clinical decision-making.

Percutaneous Coronary Intervention for Coronary Bifurcation Lesions: Latest Evidence.

PURPOSE OF REVIEW: This paper provides a synopsis of the best evidence to guide bifurcation percutaneous coronary intervention (PCI), with a focus on recent studies. This is with the aim of guiding the interventional cardiologist in choosing the best, evidence-based technique, to treat commonly encountered coronary bifurcations. RECENT FINDINGS: Current evidence supports the use of provisional stenting for most anatomically suitable bifurcation lesions. Newer techniques for side branch protection in provisional stenting have been developed. When a two-stent strategy is required, use of a double-kissing crush technique is favoured, particularly in left main bifurcations. For bifurcation PCI, as in all complex procedures, intravascular imaging plays a key adjunctive role in improving procedural success. PCI for coronary bifurcation lesions is an ever-growing field with significant advancements in techniques and technology.

The Role of Fractional Flow Reserve and Instantaneous Wave-Free Ratio Measurements in Patients with Acute Coronary Syndrome.

PURPOSE OF REVIEW: The role of fractional flow reserve to guide revascularization in patients with stable angina is well established. The instantaneous wave-free ratio (iFR) is an emerging adenosine-free resting index that is non-inferior to FFR and has potential to streamline the functional evaluation of coronary artery disease. The feasibility and utility of intracoronary physiology in patients with acute coronary syndrome (ACS) is unclear. This review will discuss the physiological principles and validity of using FFR and iFR in patients presenting with ACS. We will also provide an overview of the available evidence for their role in guiding revascularization in this patient group. RECENT FINDINGS: The use of intracoronary physiology in culprit lesions of patients presenting with STEMI is not recommended and its accuracy is uncertain in patients with NSTEMI. In contrast, the physiological assessment of non-culprit vessels with FFR and IFR is a reliable measure of lesion-specific ischemia. Recent studies have demonstrated that FFR-guided revascularization of non-culprit lesions improves clinical outcomes although the role of iFR in this patient cohort is unknown. Physiology-guided revascularization of non-culprit ACS lesions improves clinical outcomes. Future studies investigating the complementary role of plaque morphology, biomechanics, and systemic inflammation may provide clinicians with a more comprehensive framework to guide treatment decisions.

Outcomes in patients with peripheral vascular disease following percutaneous coronary intervention.

OBJECTIVES: To evaluate the clinical characteristics and outcomes of patients with peripheral vascular disease (PVD) undergoing percutaneous coronary intervention (PCI) in a contemporary setting, and to determine whether use of drug-eluting stents (DESs) improves outcomes. BACKGROUND: PVD was an independent risk factor for adverse outcomes following PCI in the bare-metal stent (BMS) era. It is not known whether outcomes in these patients have improved with advances in interventional techniques and stent technology, as they have for the general population. METHODS: Eighteen thousand three hundred and eighty patients undergoing PCI from an Australian registry between 2005 and 2013 were studied. Clinical and procedural data, 30-day and 12-month outcomes were compared in those with and without a reported history of PVD. Outcomes were also compared between patients with PVD who received DES and those who received BMS. Long-term mortality was compared using Australian National Death Index (NDI) linkage. RESULTS: Patients with PVD (n = 1,251, 6.8%) were older and had more prevalent diabetes, hypertension, cerebrovascular disease, heart failure, renal impairment, ostial lesions, left main, and multi-vessel disease (p < 0.001). Patients with PVD had significantly higher rates of major adverse cardiovascular events (MACEs) compared with those without PVD, in-hospital (5.7% vs. 4.1%, p < 0.008), at 30-days (8.6% vs. 5.8%, p < 0.001) and at 12-months (24.6% vs. 13.2%, p < 0.001). At 4.9 ± 2.6 years follow-up, there was significantly greater mortality in the PVD group. PVD patients who received DES experienced significantly less MACE than PVD patients treated with BMS at 30-days (4.8 vs. 10.1%, p < 0.001) and 12-months (19.4 vs. 26.4%, p < 0.005). CONCLUSIONS: PVD is an independent predictor of adverse outcomes in patients undergoing PCI. PVD patient who received DES had improved outcomes compared with those receiving BMS.

Ventricular Standstill Following Intravenous Erythromycin and Borderline Hypokalemia.

Ventricular standstill (VS) is a potentially fatal arrhythmia that is usually associated with syncope, if prolonged and is rarely asymptomatic[1]. Its mechanism involves either a lack of supraventricular impulse or an interruption in the transmission of these signals from the atria to the ventricles, resulting in a sudden loss of cardiac output[2]. Although rare, ventricular arrhythmias have been associated with intravenous (IV) erythromycin. However, to our knowledge, VS has not been reported following the administration of IV erythromycin. The Authors describe a rare case of asymptomatic VS and subsequent third-degree atrioventricular block, following the administration of IV erythromycin in a 49-year-old woman with borderline hypokalemia. Through this case, the Authors highlight the importance of cardiac monitoring and electrolyte replacement when administering IV erythromycin, as well as discuss several other mechanisms that contribute to ventricular arrhythmias. LEARNING POINTS: Intravenous erythromycin is associated with prolongation of the QTc interval and ventricular arrhythmias.Ventricular standstill is a rare but potentially fatal arrhythmia, and may have an association with the administration of intravenous erythromycin.Cardiac monitoring in patients with baseline QTc prolongation and correction of electrolyte disturbances are important when administering intravenous erythromycin.

Physical activity in survivors of childhood acute lymphoblastic leukaemia.

AIM: To objectively measure levels of physical activity in children, following treatment for acute lymphoblastic leukaemia (ALL). METHODS: Nineteen children who had completed treatment for ALL 6 months-5 years prior to study enrollment wore an accelerometer for 2 weekdays and 2 weekend days. RESULTS: The children spent an average of 141 +/- 74 min/day engaged in moderate to vigorous physical activity (MVPA), an amount similar to that previously documented in healthy children. Only three of the 19 subjects averaged less MVPA than the recommended amount (at least 60 min/day). MVPA levels were significantly higher on weekdays than weekend days (P= 0.006). Overall, boys engaged in significantly more MVPA than girls (P= 0.029). MVPA time was negatively correlated with age (r =-0.80) and age at diagnosis (r =-0.87). No trend between MVPA and time off treatment or body mass index was identified. CONCLUSIONS: Survivors of childhood ALL appear to be engaging in similar amounts of MVPA as those of the healthy children and are meeting recommended levels of physical activity.