Victoria Heart Institute Foundation

Routine invasive coronary angiography (ICA) is recommended for patients presenting with non-ST-segment elevation myocardial infarction (NSTEMI), but the rate of adherence to this recommendation in Australia is not known. We sought to quantify the proportion of patients who undergo ICA and revascularization in a contemporary cohort of NSTEMI patients, and to determine predictors of clinical outcome. This was a population-based cohort study of consecutive patients transported by emergency medical services (EMS) in Victoria, Australia with chest pain who were diagnosed with NSTEMI between January 1, 2015, and June 30, 2019. Ambulance data were linked to hospital admission, emergency department, and mortality records. There were 11,040 patients attended by EMS with NSTEMI, of which 5379 patients (48.7%) underwent ICA, with 2798 patients (25.3%) proceeding to coronary revascularization. Patients who underwent ICA were younger, more frequently male, less comorbid, and more likely to originate from a major city and a higher socioeconomic status compared to those who did not. Patients who underwent ICA had lower short- and long-term mortality, and coronary angiography was independently associated with reduced mortality on Cox-regression analysis (HR 0.45, 95% CI 0.41-0.50, p < 0.001). Less than half of ambulance-transported patients with NSTEMI underwent ICA, and only a quarter of the cohort received revascularization, despite there being a survival benefit with invasive management. Although patients who do not undergo ICA are older and more comorbid, there are potentially modifiable barriers to access to care, including socioeconomic status, rurality, and sex.

Landslides are major drivers of landscape evolution. Mass-wasting events connect hillslope and channel processes through the downslope transferal of sediment, which can impact fluvial systems in a multitude of ways. Coarse sediment delivered into the channel can impact flow dynamics, alter river incision rates through the tools and cover effect, deflect reach-scale river alignment, and disrupt riverine ecosystems. The feedbacks between landslides, fluvial processes, and landscape evolution remain largely unexplored despite increasingly detailed landslide inventories, enabled by the availability of airborne lidar mapping and high-resolution topographic data. To better understand the nature of these feedbacks across varying lithologies, tectonic conditions and valley morphologies we explore post-glacial landslides (~14 ka to present) in the Fraser River valley in southwest British Columbia, Canada. We created a landslide inventory using existing literature and 2,560 km2 of new airborne lidar along the Fraser Canyon corridor, a 375-km stretch of the Fraser River, which flows through multiple regions with distinct climate, morphology, and geology. We documented ~300 landslides with areas between 2 x 103 and 2 x 106 m2. Failure types include translational bedrock slides, earthflows, and rock avalanches, which vary systematically with bedrock geology and valley morphometrics. We find more translational bedrock and earthflow failures in the broader, U-shaped valley of the northern Fraser River canyons, where sedimentary, metasedimentary, and volcanic bedrock are more common. Rock avalanches are more common in the southern Fraser River canyon, where valley walls are composed of plutonic and metamorphic rocks, however the southern region has fewer landslide features overall. These findings suggest individual failures and their combined impact on the post-glacial evolution of the Fraser River are sensitive to both the geologic and glacial history of a particular stretch of river.

Abstract ObjectivesThe PROSE trial purpose is to investigate whether the incidence of thromboembolic – related complications is reduced with a current generation mechanical prosthesis (On-X Life Technologies/CryoLife Inc. – On-X) compared with a previous generation mechanical prosthesis (St Jude Medical – SJM). The primary purpose of the initial report is to document the preoperative demographics, and the preoperative and operative risk factors by individual prosthesis and by Western and Developing populations. MethodsThe PROSE study was conducted in 29 worldwide centres and incorporated 854 subjects randomized between 2003 and 2016. The study enrollment was discontinued on August 31, 2016. The preoperative demographics incorporated age, gender, functional class, etiology, prosthetic degeneration, primary rhythm, primary valve lesion, weight, height, BSA and BMI. The preoperative and operative evaluation incorporated 24 risk factors.ResultsThe total patient population (854) incorporated On-X population (461) and the St Jude Medical population (393). There was no significant difference of any of the preoperative demographics between the On-X and SJM groups. The preoperative and operative risk factors evaluation showed there was no significant difference between the On-X and St Jude Medical populations. The preoperative and operative risk factors by valve position (aortic &amp; mitral) also documented no differentiation. The dominant preoperative demographics of the Western world population were older age, male gender, sinus rhythm, aortic stenosis, congenital aortic lesion, and mitral regurgitation. The dominant demographics of the Developing world population were rheumatic etiology, atrial fibrillation, aortic regurgitation, mixed aortic lesions, mitral stenosis and mixed mitral lesions. The Developing world group had only one significant risk factor, congestive heart failure. The majority of the preoperative and operative risk factors were significant in the Western world population. ConclusionsThe preoperative demographics do not differentiate the prostheses but do differentiate the Western and Developing world populations. The preoperative and operative risk factors do not differentiate the prostheses BUT do differentiate the Western and Developing world populations.

More than half of patients undergoing percutaneous coronary intervention (PCI) have multivessel disease (MVD). The prognostic significance of PCI in stable patients has recently been debated, but little data exists about the potential benefit of complete revascularization (CR) in stable MVD. We investigated the prognostic benefit of CR in patients undergoing PCI for stable disease. We compared CR versus incomplete revascularization (IR) in 8,436 patients with MVD. The primary outcome was all-cause mortality at 5 years. A total of 1,399 patients (17%) underwent CR during the index PCI procedure for stable disease. CR was associated with lower mortality (6.2 vs. 10.7%, p < .001) and lower repeat revascularization at 5 years (12.7 vs. 18.4%, p < .001). Multivariable-adjusted analyses indicated that CR was associated with lower mortality (HR = 0.73, 95% CI: 0.58-0.91, p = .005) and repeat revascularization at 5 years (HR = 0.78, 95% CI: 0.66-0.93, p = .005). These findings were also confirmed in propensity-matched cohorts. Subgroup analyses indicated that CR conferred survival in older patients, male patients, absence of renal disease, greater angina (CCS Class III-IV) and heart failure (NYHA Class III-IV) symptoms, and greater burden of coronary disease. In sensitivity analyses where patients with subsequent repeat revascularization events were excluded, CR remained a strong predictor for lower mortality (HR = 0.69, 95% CI: 0.54-0.89, p = .004). In this study of stable patients with MVD, CR was an independent predictor of long-term survival. This benefit was specifically seen in higher risk patient groups and indicates that CR may benefit selected stable patients with MVD.

&amp;lt;p&amp;gt;Rainforest rivers export large quantities of terrestrial materials from watersheds to the coastal ocean, with important implications for local ecosystems and global biogeochemical cycles. However, the impact of episodic disturbance on this process is a critical knowledge gap in our understanding of land-sea connections. Fjords represent a global hotspot for terrestrial carbon burial in marine sediments, yet the relative importance of typical riverine fluxes vs. mass wasting fluxes is uncertain and dynamic. Similarly, mass wasting events can generate both an instantaneous pulse and a sustained shift in the material export regime. Riverine sediment regimes also have important implications for freshwater ecosystems and fisheries resources. A recent mass wasting event in Bute Inlet &amp;amp;#8211; Homalco First Nation traditional territory and British Columbia, Canada &amp;amp;#8211; presents an important opportunity to quantify the sustained impact of such an infrequent large disturbance on the source-to-sink linkages between glacierized mountains, rivers, and fjords.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;On November 28, 2020, a landslide in the headwaters of the Elliot Creek watershed (118 km&amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt;) triggered a glacial lake outburst flood (GLOF) that eroded 3 km&amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt; of forested land and exported large volumes of water and terrestrial materials to the lower reaches of the Southgate River watershed (1986 km&amp;lt;sup&amp;gt;2&amp;lt;/sup&amp;gt;) and ultimately to the head of Bute Inlet. Here we assess river and ocean surface turbidity over four winter months following the event, in comparison to pre-event measurements taken across all seasons in recent years. River turbidity was measured on the Southgate River above and below the confluence of Elliot Creek, beginning in December 2020, and at the mouth of the Southgate and nearby Homathko Rivers prior to November 2020. Bute Inlet turbidity was measured (every month to two months) starting in May 2017.&amp;lt;/p&amp;gt;&amp;lt;p&amp;gt;Prior to the GLOF event, Southgate River turbidity ranged from a low of 3.3 &amp;amp;#177; 0.4&amp;amp;#160;FNU in the winter to a high of 71.4 FNU in the summer meltwater period. Since the event, Southgate River turbidity has been consistently elevated &amp;amp;#8805;6 times background levels recorded above Elliot Creek. At the extreme, on January 13, 2021, seven weeks after the GLOF, Southgate River mean turbidity (105.2 &amp;amp;#177; 3.3&amp;amp;#160;FNU) was 32 times the background (3.3 &amp;amp;#177; 0.4&amp;amp;#160;FNU), equating to a sustained increase in wintertime turbidity that sometimes exceeds the historical summertime peak. Given the typical coupling of turbidity with discharge, we expect further increases in turbidity with the coming freshet of 2021; the first meltwater season following the GLOF. These results suggest the potential for a sustained shift in the seasonal turbidity regime of the Southgate River and the estuarine waters of Bute Inlet. The elevated turbidity signals broader changes to: sediment export and carbon burial, the depth and seasonality of light penetration, river water quality, and spawning habitat quality for anadromous fish. Ongoing monitoring will be used to characterize the duration, dynamics, and potential recovery of elevated turbidity regimes across the land-to-ocean aquatic continuum in Bute Inlet.&amp;lt;/p&amp;gt;

&lt;sec&gt;&lt;st&gt;Background&lt;/st&gt; Renal function-based contrast dosing minimises renal injury following percutaneous coronary intervention (PCI). The ratio (&lt;it&gt;R&lt;/it&gt;) of contrast volume:glomerular filtration rate (GFR) has been studied but its prognostic relevance is unknown. &lt;/sec&gt; &lt;sec&gt;&lt;st&gt;Aim&lt;/st&gt; To establish the relationship between &lt;it&gt;R&lt;/it&gt; and mortality; and define a ‘prognostic’ threshold (&lt;it&gt;R&lt;inf&gt;T&lt;/inf&gt; &lt;/it&gt;) for contrast in PCI for stable disease, non ST-elevation ACS (NSTEACS) and ST-elevation ACS (STEACS). &lt;/sec&gt; &lt;sec&gt;&lt;st&gt;Method&lt;/st&gt; We evaluated 44 082 non-dialysis patients between 2008–2014. GFR was calculated using CG, CKD-EPI and MDRD equations. &lt;it&gt;R&lt;/it&gt; was determined for each patient and its relationship with mortality was modelled mathematically and analysed using Cox regression and adjusted ROC curve analyses. &lt;/sec&gt; &lt;sec&gt;&lt;st&gt;Results&lt;/st&gt; Multivariable analyses identified &lt;it&gt;R&lt;/it&gt; as an independent predictor of 3 year mortality (HR=1.03, 95% CI: 1.02 to 1.04, p&lt;0.001). There was an exponential relationship between &lt;it&gt;R&lt;/it&gt; and mortality; for every unit increase in &lt;it&gt;R&lt;/it&gt;, 3 year mortality increased by 13%–14% regardless of PCI indication. Adjusted analyses indicated &lt;it&gt;R&lt;inf&gt;T&lt;/inf&gt; &lt;/it&gt; was consistently higher in stable disease (&lt;it&gt;R&lt;inf&gt;T&lt;/inf&gt; &lt;/it&gt;=7.7–8.3) compared to NSTEACS (&lt;it&gt;R&lt;inf&gt;T&lt;/inf&gt; &lt;/it&gt;=5.3–5.7) and STEACS (&lt;it&gt;R&lt;inf&gt;T&lt;/inf&gt; &lt;/it&gt;=5.3–5.7). &lt;/sec&gt; &lt;sec&gt;&lt;st&gt;Conclusion&lt;/st&gt; This study advocates a &lt;it&gt;R&lt;inf&gt;T&lt;/inf&gt; &lt;/it&gt;=7.7–8.3 for stable disease and &lt;it&gt;R&lt;inf&gt;T&lt;/inf&gt; &lt;/it&gt;=5.3–5.7 for NSTEACS/STEACS. This is greater than previously reported but implies greater contrast volumes may ultimately be tolerated in the contemporary PCI era. &lt;fig loc="float" id="F1"&gt;&lt;no&gt;Abstract 4 Figure 1&lt;/no&gt;&lt;caption&gt; (A) Cox regression analyses (3-year mortality) and (B) Adjusted ROC curve analysis (1,2 and 3-year mortality) &lt;/caption&gt; &lt;link locator="04_F001"&gt;&lt;/fig&gt; &lt;/sec&gt;