Practice Patterns in the Interventional Treatment of Coronary Bifurcation Lesions: A Global Survey

OBJECTIVES

The study aim was to assess current procedural strategies and perceptions for percutaneous coronary intervention (PCI) involving bifurcations.

METHODS

We distributed an online survey via email (8050 invitations) and social media.

RESULTS

Among 440 responders, median annual PCI volumes were 15 cases (interquartile range [IQR], 10-29 cases) for left main (LM) and 50 cases (IQR, 27-73 cases) for non-LM (nLM) bifurcation lesions. Radial access use was reported in 51% of LM and 82% of nLM cases. An upfront 2-stent strategy, most commonly double-kissing (DK) crush, was reported in 49% of LM and 29% of nLM lesions. Bailout stenting during provisional stenting was reported in 26% of LM-PCIs, usually using the T and protrusion technique. In provisional stenting cases, most operators (<35%) did not report predilating the side branch, but routinely postdilated after successful provisional stenting (>85%), most often using both kissing-balloon inflation and the proximal optimization technique. Intravascular imaging was used in 80% of LM and 46% of nLM cases.

CONCLUSIONS

Among the survey responders, the DK crush technique was the most frequently used 2-stent strategy for bifurcation PCIs. For LM lesions, bailout stenting was performed after provisional strategy in approximately 25% of cases. For nLM lesions, use of intravascular imaging and coronary physiology was lower than for LM lesions.

Double kissing crush bifurcation stenting: step-by-step troubleshooting

The double kissing crush (DK crush) is the most studied two-stent coronary bifurcation stenting strategy. While published data support its use, DK crush can be challenging to perform. In this review we provide a detailed step-by-step description and troubleshooting for each stage of the DK crush technique.

Preprocedure Planning for Chronic Total Occlusion Percutaneous Coronary Intervention: The Separation Is in the Preparation

To perform chronic total occlusion percutaneous coronary intervention safely, efficiently, and successfully, adequate time must be dedicated to thorough preprocedural planning. This process should encompass a patient encounter, becoming fully familiarized with the patient's clinical traits, a detailed review of coronary anatomy, laying out an algorithmic procedural approach and making any relevant plans for actions that will enhance intraprocedural safety.

Temporal Trends in Chronic Total Occlusion Percutaneous Coronary Interventions: Insights From the PROGRESS-CTO Registry

BACKGROUND

Chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has significantly evolved in recent years.

METHODS

We compared the clinical, angiographic, and technical characteristics, as well as procedural outcomes of CTO-PCIs in a multicenter registry between the "early era" (2012-2016) and the "current era" (2017-2019).

RESULTS

Current era patients more often had stage III or IV angina compared with early era patients (71% vs 66%, respectively; P=.03) and were less likely to undergo ad hoc CTO-PCI (13% vs 16%, respectively; P=.04). The J-CTO score was slightly lower in the current era patients vs the early era patients (2.3 ± 1.4 vs 2.5 ± 1.3, respectively; P=.04). Use of antegrade wire escalation increased in the current era (92% vs 83% in the early era patients; P<.001) whereas use of retrograde crossing decreased (29% vs 39% in the early era; P<.001) and antegrade/ dissection re-entry decreased (23% vs 32% in the early era; P<.001). Technical success rates (85% in the current era vs 86% in the early era; P=.69) and procedural success rates (83% in the current era vs 85% in the early era; P=.15) were similar, whereas the incidence of in-hospital major cardiovascular events decreased in the current era (2% vs 3% in the early era; P=.04).

CONCLUSIONS

During recent years, ad hoc CTO-PCI decreased along with decreasing use of retrograde crossing and antegrade dissection and re-entry. Technical and procedural success rates remained stable, whereas the incidence of in-hospital MACE decreased.

Impact of concomitant treatment of non-chronic total occlusion lesions at the time of chronic total occlusion intervention

BACKGROUND

During chronic total occlusion (CTO) percutaneous coronary intervention (PCI), sometimes non-CTO lesions are also treated.

METHODS

We compared the clinical and procedural characteristics and outcomes of CTO PCIs with and without concomitant treatment of a non-CTO lesion in a contemporary multicenter CTO registry.

RESULTS

Of the 3598 CTO PCIs performed at 21 centers between 2012 and 2018, 814 (23%) also included PCI of at least one non-CTO lesion. Patients in whom non-CTO lesions were treated were older (65 ± 10 vs. 64 ± 10 years, p = 0.03), more likely to present with an acute coronary syndrome (32% vs. 23%, p < 0.01), and less likely to undergo PCI of a right coronary artery (RCA) CTO (46% vs. 58%, p < 0.01). The most common non-CTO lesion location was the left anterior descending artery (31%), followed by the circumflex (29%) and the RCA (25%).Combined non-CTO and CTO-PCI procedures had similar technical (88% vs. 87%, p = 0.33) and procedural (85% vs. 85%, p = 0.74) success and major in-hospital complication rates (3.4% vs. 2.7%, p = 0.23), but had longer procedure duration (131 [88, 201] vs. 117 [75, 179] minutes, p < 0.01), higher patient air kerma radiation dose (3.0 [1.9, 4.8] vs. 2.8 [1.5, 4.6] Gray, p < 0.01) and larger contrast volume (300 [220, 380] vs. 250 [180, 350] ml, p < 0.01).

CONCLUSIONS

Combined CTO PCI with PCI of non-CTO lesions is associated with similar success and major in-hospital complication rates compared with cases in which only CTOs were treated, but requires longer procedure duration and higher radiation dose and contrast volume.

The Impact of Peripheral Artery Disease in Chronic Total Occlusion Percutaneous Coronary Intervention (Insights From PROGRESS-CTO Registry)

The impact of peripheral artery disease (PAD) in patients undergoing chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has received limited study. We reviewed 3999 CTO PCIs performed in 3914 patients between 2012 and 2018 at 25 centers, 14% of whom had a history of PAD. We compared the clinical and angiographic characteristics and procedural outcomes of patients with versus without history of PAD. Patients with PAD were older (67 ± 9 vs 64 ± 10 years, P < .001) and had a higher prevalence of cardiovascular risk factors. They also had more complex lesions as illustrated by higher Japanese CTO score (2.7 ± 1.2 vs 2.4 ± 1.3, P < .001). In patients with PAD, the final crossing technique was less often antegrade wire escalation (40% vs 51%, P < .001) and more often the retrograde approach (23 vs 20%, P < .001) and antegrade dissection/reentry (20% vs 16%, P < .001). Technical success was similar between the 2 study groups (84% vs 87%, P = .127), but procedural success was lower for patients with PAD (81% vs 85%, P = .015). The incidence of in-hospital major adverse cardiac events was higher among patients with PAD (3% vs 2%, P = .046). In conclusion, patients with PAD undergoing CTO PCI have more comorbidities, more complex lesions, and lower procedural success.

A Case-Based Illustration of the Use of Microcatheter Pressure Transduction for Confirmation of Distal Wire Position in Complex Percutaneous Coronary Intervention

Determining distal wire position during chronic total occlusion percutaneous coronary intervention can be challenging. We describe a novel technique that can help confirm distal true lumen wire position. A microcatheter is advanced distally over the wire and after removing the guidewire, it is connected to a manifold for pressure transduction: an arterial waveform is indicative of intra-luminal position.

A Case-Based Illustration of a Dual-Operator, Dual Microcatheter Technique for Side Branch Wiring

Wiring a side branch through a dual lumen microcatheter is typically performed in sequential fashion: the microcatheter position is modified, followed by wiring attempts, all performed by a single operator. We describe a dual operator technique, in which positioning of the dual lumen microcatheter and guidewire advancement are performed simultaneously. This method can be used for particularly challenging wiring scenarios. We provide two case examples illustrating how this technique could facilitate the success and efficiency of side branch wiring.

Left Main Chronic Total Occlusion Percutaneous Coronary Intervention: A Case Series

BACKGROUND

Left main coronary artery (LMCA) chronic total occlusion (CTO) percutaneous coronary intervention (PCI) has received limited study.

METHODS

We reviewed 4436 CTO-PCIs performed in 4340 patients between 2012 and 2018 at 25 sites. LMCA-CTO-PCI was performed in 20 cases (0.45%). We examined the clinical and angiographic characteristics and procedural outcomes of these cases.

RESULTS

Mean patient age was 68 ± 11 years and 65% were men. Most patients (85%) had undergone prior coronary artery bypass graft surgery and had a protected left main. Mean J-CTO score was 2.7 ± 1.3, mean PROGRESS-CTO score was 1.3 ± 1.1, and mean PROGRESS-CTO Complications score was 3.8 ± 1.9. Antegrade-wire escalation was the most common successful crossing strategy (50%), followed by retrograde crossing (30%) and antegrade dissection/re-entry (10%). Technical and procedural success rates were both 85%. One patient with failed LMCA-CTO-PCI had periprocedural myocardial infarction. Median procedure time was 178 minutes (interquartile range [IQR], 123-250 minutes), median contrast volume was 190 mL (IQR, 133-339 mL), and patient air kerma radiation dose was 2.6 Gray (IQR, 1.3-3.9 Gray).

CONCLUSIONS

LMCA-CTO-PCI is infrequent, is performed mostly in patients with prior coronary artery bypass graft surgery, and is associated with good procedural outcomes.

Treating saphenous vein graft lesions: Drug-eluting stents are not the answer!

Saphenous vein graft (SVG) percutaneous coronary intervention carries high rates of acute (no reflow and periprocedural myocardial infarction) and long-term (restenosis and re-occlusion) complications. Long-term follow-up from the two largest trials of drug-eluting vs. bare metal stents in SVG lesions (The Drug-Eluting Stents vs. Bare Metal Stents In Saphenous Vein graft Angioplasty and Is Drug-Eluting-Stenting Associated with Improved Results in Coronary Artery Bypass Grafts? Trial) definitely show no difference between the two stent types, suggesting that bare metal stents should be preferred given lower cost. Since SVG stenting remains associated with high failure rates, alternative treatment strategies, such as intervention of the corresponding native coronary artery lesions, may represent the future direction of the field.

Single molecule RNA sequencing uncovers trans-splicing and improves annotations in Anopheles stephensi

Single molecule real-time (SMRT) sequencing has recently been used to obtain full-length cDNA sequences that improve genome annotation and reveal RNA isoforms. Here, we used one such method called isoform sequencing from Pacific Biosciences (PacBio) to sequence a cDNA library from the Asian malaria mosquito Anopheles stephensi. More than 600 000 full-length cDNAs, referred to as reads of insert, were identified. Owing to the inherently high error rate of PacBio sequencing, we tested different approaches for error correction. We found that error correction using Illumina RNA sequencing (RNA-seq) generated more data than using the default SMRT pipeline. The full-length error-corrected PacBio reads greatly improved the gene annotation of Anopheles stephensi: 4867 gene models were updated and 1785 alternatively spliced isoforms were added to the annotation. In addition, six trans-splicing events, where exons from different primary transcripts were joined together, were identified in An. stephensi. All six trans-splicing events appear to be conserved in Culicidae, as they are also found in Anopheles gambiae and Aedes aegypti. The proteins encoded by trans-splicing events are also highly conserved and the orthologues of these proteins are cis-spliced in outgroup species, indicating that trans-splicing may arise as a mechanism to rescue genes that broke up during evolution.

Effects of short-term continuous positive airway pressure on myocardial sympathetic nerve function and energetics in patients with heart failure and obstructive sleep apnea: a randomized study

BACKGROUND

Heart failure with reduced ejection fraction and obstructive sleep apnea (OSA), 2 states of increased metabolic demand and sympathetic nervous system activation, often coexist. Continuous positive airway pressure (CPAP), which alleviates OSA, can improve ventricular function. It is unknown whether this is due to altered oxidative metabolism or presynaptic sympathetic nerve function. We hypothesized that short-term (6-8 weeks) CPAP in patients with OSA and heart failure with reduced ejection fraction would improve myocardial sympathetic nerve function and energetics.

METHODS AND RESULTS

Forty-five patients with OSA and heart failure with reduced ejection fraction (left ventricular ejection fraction 35.8±9.7% [mean±SD]) were evaluated with the use of echocardiography and 11C-acetate and 11C-hydroxyephedrine positron emission tomography before and ≈6 to 8 weeks after randomization to receive short-term CPAP (n=22) or no CPAP (n=23). Work metabolic index, an estimate of myocardial efficiency, was calculated as follows: (stroke volume index×heart rate×systolic blood pressure÷Kmono), where Kmono is the monoexponential function fit to the myocardial 11C-acetate time-activity data, reflecting oxidative metabolism. Presynaptic sympathetic nerve function was measured with the use of the 11C-hydroxyephedrine retention index. CPAP significantly increased hydroxyephedrine retention versus no CPAP (Δretention: +0.012 [0.002, 0.021] versus -0.006 [-0.013, 0.005] min(-1); P=0.003). There was no significant change in work metabolic index between groups. However, in those with more severe OSA (apnea-hypopnea index>20 events per hour), CPAP significantly increased both work metabolic index and systolic blood pressure (P<0.05).

CONCLUSIONS

In patients with heart failure with reduced ejection fraction and OSA, short-term CPAP increased hydroxyephedrine retention, indicating improved myocardial sympathetic nerve function, but overall did not affect energetics. In those with more severe OSA, CPAP may improve cardiac efficiency. Further outcome-based investigation of the consequences of CPAP is warranted.

CLINICAL TRIAL REGISTRATION URL

http://www.clinicaltrials.gov. Unique identifier: NCT00756366.

Outcomes and reasons for dacryocystorhinostomy (DCR) at KCMC, a Tanzanian referral hospital, 2001-2006

BACKGROUND

External dacryocystorhinostomy (DCR) is a surgical intervention aimed to treat blocked nasolacrimal ducts of almost all causes. To date there is only limited data available from the Sub Saharan African setting.

OBJECTIVES

This study aimed to provide further information of the outcomes of DCR in Africa.

METHODS

Records of all patients undergoing external DCR operations from January 2001 to April 2006 were systematically searched. 55 patients were identified and notes were available for 45 patients.

RESULTS

Discharge and epiphora were resolved in 90.9% (30/33) and 84.4% (27/32) of patients respectively. Over half the cases (51.1%) were children. The commonest reason for operation was chronic dacryocystitis (51.1%). Outcomes for DCR were not significantly different for either children or adults and a clear improvement of symptoms was found in the vast majority of cases.

CONCLUSION

This study provides information on the outcomes of DCR in the African population. An 84.4% cure rate of epiphora and 90.9% cure rate of discharge is comparable with findings in other developing countries. This study supports the continued use of this intervention in skilled hands for treatment of blocked nasolacrimal duct.

Extent and economic effect of heat loads on dairy cattle production in Australia

OBJECTIVE

To investigate the extent of heat load problems, caused by the combination of excessive temperature and humidity, in Holstein-Friesian cows in Australia. Also, to outline how milk production losses and consequent costs from this can be estimated and minimised.

PROCEDURES

Long-term meteorological data for Australia were analysed to determine the distribution of hot conditions over space and time. Fifteen dairy production regions were identified for higher-resolution data analysis. Both the raw meteorological data and their integration into a temperature-humidity thermal index were compiled onto a computer program. This mapping software displays the distribution of climatic patterns, both Australia-wide and within the selected dairying regions. Graphical displays of the variation in historical records for 200 locations in the 15 dairying regions are also available. As a separate study, production data from research stations, on-farm trials and milk factory records were statistically analysed and correlated with the climatic indices, to estimate production losses due to hot conditions.

RESULTS

Both milk yields and milk constituents declined with increases in the temperature-humidity index. The onset and rate of this decline are dependent on a number of factors, including location, level of production, adaptation, and management regime. These results have been integrated into a farm-level economic analysis for managers of dairy properties.

CONCLUSION

By considering the historical patterns of hot conditions over time and space, along with expected production losses, managers of dairy farms can now conduct an economic evaluation of investment strategies to alleviate heat loads. These strategies include the provision of sprinklers, shade structures, or combinations of these.

Associations between lens features assessed in the Oxford Clinical Cataract Classification and Grading System

PURPOSE

To study the associations between eleven lens features graded according to the Oxford Clinical Cataract Classification and Grading System (OCCCGS).

METHOD

560 subjects taking part in the Melton Eye Study had their lenses graded according to the OCCCGS by one of two examiners. Associations between features were examined using log-linear models for categorised grades. Adjustment was made for age, sex and grader.

RESULTS

Within subjects, the two nuclear features, white nuclear scatter and brunescence, are closely related with one another, as are coronary flakes and focal-dots, but these two groupings are negatively associated. Cortical spoke, fibrefolds and waterclefts are all associated with one another and this group is positively associated with coronary flakes and focal-dots. Posterior subcapsular and anterior subcapsular opacity are associated with one another and with cortical spokes. A within-eye analysis gives similar results.

CONCLUSION

These associations may be important in defining cataract subtypes and in identifying minor features that indicate early cataract development.

LOCS III versus the Oxford Clinical Cataract Classification and Grading System for the assessment of nuclear, cortical and posterior subcapsular cataract

PURPOSE

To compare two methods of cataract grading for nuclear cataract, cortical cataract and posterior subcapsular cataract.

METHODS

The Melton Eye Study is an English community-based epidemiological study of the natural history of eye disease in people aged 55 to 74 years. The lenses of both eyes of 560 subjects were graded at the slit lamp using two cataract grading systems. The Oxford Clinical Cataract Classification and Grading System (OCCCGS) employs standard diagrams and Munsell colour samples for the grading of cortical, posterior subcapsular and nuclear cataract. The Lens Opacities Classification System III (LOCS III) uses photographic transparencies of the lens as standards. In both systems a decimalised score is assigned. We also graded the LOCS III standard images using the OCCCGS. Interobserver variation was calculated for both grading systems. Linear calibration lines are plotted for each type of lens opacity.

RESULTS

The relationship between LOCS III and OCCCGS for nuclear cataract and posterior subcapsular cataract is linear. The relationship for cortical cataract is linear once the LOCS III scores are squared. The intervals between the LOCS III images when ranked by the human eye using the OCCCGS are linear. Interobserver variation for both systems is good.

CONCLUSIONS

The linear calibration lines may be used to convert from one system to another and will be useful in comparing studies or performing meta-analysis. These results show that data from cataract studies using different clinical grading schemes can be compared.

Prevalence of lenticular abnormalities in a population-based study: Oxford Clinical Cataract Grading in the Melton Eye Study

PURPOSE

To describe the distribution of the 11 features assessed by the Oxford Clinical Cataract Classification and Grading System (OCCCGS) in a population-based study.

METHODS

The Melton Eye Study is an English community-based epidemiological study of the natural history of eye disease in people aged 55 to 74 years. Both lenses of 560 subjects were graded at the slit lamp using a decimalised version of the OCCCGS. Subject prevalences were estimated by logistic regression and the extent, when present, against normal errors regression.

RESULTS

White nuclear scatter (WNS), brunescence, cortical spoke (CS), anterior subcapsular opacity (ASC), fibre folds (FF), waterclefts (WC) and perinuclear retro-dots all increased with age (p < 0.05). Posterior subcapsular opacity (PSC), vacuoles, focal dots (FD) and coronary flakes (CF) did not significantly increase with age. Subject prevalences of the features and the mean Oxford scores when present were: WNS (1.33), brunescence (0.88), CS 36% (0.34), PSC 11% (0.52), ASC 2% (0.53), FF 18% (0.53), WC 17% (0.29), retro-dots 11% (1.15), vacuoles 59% (0.43), FD 98% (1.79) and CF 39% (1.24). Significantly more common in women were both coronary flakes (p < 0.001) and waterclefts (p < 0.05).

CONCLUSIONS

These are the first data on the distribution of these minor lesions in a population-based study. Coronary flakes and waterclefts are more common in women.

Innovative clinical teaching

Participating faculty are entering their third year using this type of student rotation and have found that it continues to be a positive teaching-learning experience for faculty, staff, and students. It has enabled a greater number of students to enjoy a positive clinical experience in areas that previously were limited to a smaller number of students. Perhaps this strategy, or a part of it, may be of benefit to other nurse educators as a method of improving undergraduate clinical experiences.

A thermodynamic view of polymer degradation, and its application to extensive sonication of DNA

A simple thermodynamic theory is developed, which predicts (in agreement with a wide variety of other theoretical approaches and experimental results) that for simple polymers the most probable Schulz distribution of fragments will be obtained in a polymer degradation process that is allowed to proceed to a dynamic equilibrium. When the same method is applied to a double-stranded polymer like DNA, however, it predicts that some narrowing of this distribution may occur in conjunction with a limited amount of base unpairing at the fragment termini. The compatibility of this prediction with the experimental results of long-time sonication of DNA is considered.