Operative Teaching of Coronary Bypass and Need for Repeat Catheterization: Does it Matter Who is Sewing?

OBJECTIVE: There are no studies to date comparing the patency of coronary bypass grafts constructed by attending surgeons versus trainees and the potential consequences of any such disparities. We explored this issue by comparing the patency of individual anastomoses performed by residents versus the attending surgeon. DESIGN: We reviewed 765 continuous cases performed by a single surgeon which involved at least 1 coronary bypass anastomosis, totaling 2,173 distal anastomoses. At a median follow-up time of 36 months (interquartile range 20.5-47.3), 83 (10.9%) patients had undergone 110 cardiac catheterization procedures after their original operation for various indications. This angiographic information provided the data for our comparison cohorts. SETTING: Cardiac surgery practice within an academic setting PARTICIPANTS: Adult patient undergoing coronary bypass grafting RESULTS: Of the 83 patients that underwent repeat catheterization, 23 (27.7%) were resident cases, 25 (30.1%) were attending cases and 35 (42.2%) were mixed. There were 4/83 (4.8%) patients with angiographic evidence of internal mammary artery graft compromise of which 3/4 (75%) had been constructed by the attending surgeon. Angiographic evidence of saphenous vein graft compromise was appreciated in 16/83 (19.3%) patients of which 9/16 (56.3%) of the grafts were constructed by the attending surgeon. CONCLUSIONS: Liberal involvement of surgical trainees as primary operators in coronary revascularization cases led to equivalent rates of postoperative ischemic complications between the attending and resident groups. The outcome equivalence was also maintained when evaluated at the individual anastomosis patency level between the 2 groups. We conclude that academic programs should continue providing trainees significant experience as primary operating surgeons without fear of clinical outcome compromise.

Identifying high risk clinical phenogroups of pulmonary hypertension through a clustering analysis.

INTRODUCTION: The classification and management of pulmonary hypertension (PH) is challenging due to clinical heterogeneity of patients. We sought to identify distinct multimorbid phenogroups of patients with PH that are at particularly high-risk for adverse events. METHODS: A hospital-based cohort of patients referred for right heart catheterization between 2005-2016 with PH were included. Key exclusion criteria were shock, cardiac arrest, cardiac transplant, or valvular surgery. K-prototypes was used to cluster patients into phenogroups based on 12 clinical covariates. RESULTS: Among 5208 patients with mean age 64±12 years, 39% women, we identified 5 distinct multimorbid PH phenogroups with similar hemodynamic measures yet differing clinical outcomes: (1) "young men with obesity", (2) "women with hypertension", (3) "men with overweight", (4) "men with cardiometabolic and cardiovascular disease", and (5) "men with structural heart disease and atrial fibrillation." Over a median follow-up of 6.3 years, we observed 2182 deaths and 2002 major cardiovascular events (MACE). In age- and sex-adjusted analyses, phenogroups 4 and 5 had higher risk of MACE (HR 1.68, 95% CI 1.41-2.00 and HR 1.52, 95% CI 1.24-1.87, respectively, compared to the lowest risk phenogroup 1). Phenogroup 4 had the highest risk of mortality (HR 1.26, 95% CI 1.04-1.52, relative to phenogroup 1). CONCLUSIONS: Cluster-based analyses identify patients with PH and specific comorbid cardiometabolic and cardiovascular disease burden that are at highest risk for adverse clinical outcomes. Interestingly, cardiopulmonary hemodynamics were similar across phenogroups, highlighting the importance of multimorbidity on clinical trajectory. Further studies are needed to better understand comorbid heterogeneity among patients with PH.

Association of Pulmonary Artery Pulsatility Index With Adverse Cardiovascular Events Across a Hospital-Based Sample.

BACKGROUND: The pulmonary artery pulsatility index (PAPi), calculated from the ratio of the pulmonary artery pulse pressure to right atrial pressure, is a predictor of right ventricular failure after inferior myocardial infarction and left ventricular assist device implantation. Whether PAPi is associated with adverse outcomes across a heterogeneous population is unknown. METHODS: We examined consecutive patients undergoing right heart catheterization between 2005 and 2016 in a hospital-based cohort. Multivariable Cox models were utilized to examine the association between PAPi and all-cause mortality, major adverse cardiac events, and heart failure hospitalizations. RESULTS: We studied 8285 individuals (mean age 63 years, 39% women) with median PAPi across quartiles 1.7, 2.8, 4.2, and 8.7, who were followed over a mean follow-up of 6.7±3.3 years. Patients in the lowest PAPi quartile had a 60% greater risk of death compared with the highest quartile (multivariable-adjusted hazard ratio, 1.60 [95% CI, 1.36-1.88], P<0.001) and a higher risk of major adverse cardiac events and heart failure hospitalizations (hazard ratio, 1.80 [95% CI, 1.56-2.07], P<0.001 and hazard ratio, 2.08 [95% CI, 1.76-2.47], P<0.001, respectively). Of note, patients in quartiles 2 and 3 also had increased risk of cardiovascular events compared with quartile 4 (multivariable P<0.05 for all). CONCLUSIONS: Compared with the highest PAPi quartile, patients in PAPi quartiles 1 to 3 had a greater risk of all-cause mortality, major adverse cardiac events, and heart failure hospitalizations, with greatest risk observed in the lowest quartile. A low PAPi, even at values higher than previously reported, may serve an important role in identifying high-risk individuals across a broad spectrum of cardiovascular disease.

High-resolution cardiovascular function confirms functional orthology of myocardial contractility pathways in zebrafish.

Phenotype-driven screens in larval zebrafish have transformed our understanding of the molecular basis of cardiovascular development. Screens to define the genetic determinants of physiological phenotypes have been slow to materialize as a result of the limited number of validated in vivo assays with relevant dynamic range. To enable rigorous assessment of cardiovascular physiology in living zebrafish embryos, we developed a suite of software tools for the analysis of high-speed video microscopic images and validated these, using established cardiomyopathy models in zebrafish as well as modulation of the nitric oxide (NO) pathway. Quantitative analysis in wild-type fish exposed to NO or in a zebrafish model of dilated cardiomyopathy demonstrated that these tools detect significant differences in ventricular chamber size, ventricular performance, and aortic flow velocity in zebrafish embryos across a large dynamic range. These methods also were able to establish the effects of the classic pharmacological agents isoproterenol, ouabain, and verapamil on cardiovascular physiology in zebrafish embryos. Sequence conservation between zebrafish and mammals of key amino acids in the pharmacological targets of these agents correlated with the functional orthology of the physiological response. These data provide evidence that the quantitative evaluation of subtle physiological differences in zebrafish can be accomplished at a resolution and with a dynamic range comparable to those achieved in mammals and provides a mechanism for genetic and small-molecule dissection of functional pathways in this model organism.

Patient and Provider Risk in Managing ST-Elevation Myocardial Infarction During the COVID-19 Pandemic: A Decision Analysis.

BACKGROUND: The optimal treatment strategy for treating ST-segment-elevation myocardial infarction (STEMI) in context of the coronavirus disease 2019 (COVID-19) pandemic is unclear given the potential risk of occupational exposure during primary percutaneous coronary intervention (PPCI). We quantified the impact of different STEMI treatment strategies on patient outcomes and provider risk in context of the COVID-19 pandemic. METHODS: Using a decision-analytic framework, we evaluated the effect of PPCI versus the pharmaco-invasive strategy for managing STEMI on 30-day patient mortality and individual provider infection risk based on presence of cardiogenic shock, suspected coronary territory, and presence of known or presumptive COVID-19 infection. RESULTS: For patients with low suspicion for COVID-19, PPCI had mortality benefit over the pharmaco-invasive strategy, and the risk of cardiac catheterization laboratory provider infection remained very low (<0.25%) across all subgroups. For patients with presumptive COVID-19 with cardiogenic shock, PPCI offered substantial mortality benefit to patients relative to the pharmaco-invasive strategy (7.9% absolute decrease in 30-day mortality), but also greater risk of provider infection (2.3% absolute increase in risk of provider infection). For patients with presumptive COVID-19 with nonanterior STEMI without cardiogenic shock, PPCI offered a 0.4% absolute mortality benefit over the pharmaco-invasive strategy with a 0.2% greater absolute risk of provider infection, and the tradeoff between patient and provider risk with PPCI became more apparent in sensitivity analysis with more severe COVID-19 infections. CONCLUSIONS: Usual care with PPCI remains the appropriate treatment strategy in the majority of cases presenting with STEMI in the setting of the COVID-19 pandemic. However, utilization of a pharmaco-invasive strategy in selected patients with STEMI with presumptive COVID-19 and low likelihood of mortality from STEMI and use of preventive strategies such as preprocedural intubation in high risk patients when PPCI is the preferred strategy may be reasonable to reduce provider risk of COVID-19 infection.

Comparison of sixty-four-slice multidetector computed tomographic coronary angiography to coronary angiography with intravascular ultrasound for the detection of transplant vasculopathy.

Coronary allograft vasculopathy (CAV) is the most important limitation to long-term survival in adult heart transplant recipients and is difficult to detect without intravascular ultrasound (IVUS). We systematically evaluated the image quality of 64-slice multidetector computed tomographic (MDCT) coronary angiography in heart transplant recipients and tested the hypothesis that this modality is comparable to invasive coronary angiography with IVUS for the detection of CAV. Heart transplant recipients (n = 20) underwent invasive coronary angiography with IVUS and MDCT coronary angiography with a 64-slice scanner. Images were systematically analyzed for image quality and the presence of CAV. In addition, multidetector computed tomography and quantitative coronary angiography were used to measure lumen diameters at prespecified locations. Image quality analysis showed that, despite high mean heart rates (77 +/- 7 beats/min) and body mass index (29.5 +/- 5.3 kg/m(2)), 83% of coronary segments were graded as of excellent or good image quality. On average, 95 +/- 9% of the overall visualized length of the coronary arteries was imaged without motion artifacts, and the mean contrast-to-noise ratio was 11.3 +/- 4.6. Compared with IVUS, multidetector computed tomography had a sensitivity of 70%, specificity of 92%, positive predictive value of 89%, and negative predictive value of 77% for the detection of CAV. MDCT vessel diameter measurements correlated well with those obtained from quantitative coronary angiography (R(2) = 0.89). In conclusion, 64-slice multidetector computed tomography provides good to excellent image quality in heart transplant recipients and has moderate to excellent test characteristics for the detection of CAV. Further, MDCT measurements of lumen diameters correlated well with quantitative coronary angiography.

Comparison of the degree of coronary stenoses by multidetector computed tomography versus by quantitative coronary angiography.

Sixteen-slice multidetector computed tomography (MDCT) and quantitative coronary angiography (QCA) were performed in 29 patients. Quantification of the degree of luminal narrowing and lesion length measurements were performed independently on MDCT and QCA at 42 sites with sufficient computed tomographic image quality. The correlation between MDCT and QCA for quantifying the degree of stenosis was excellent (r2 = 0.93), although a systematic overestimation was observed by MDCT (bias 4% +/- 8%). The correlation between MDCT and QCA was moderate with respect to lesion length (r2 = 0.54). In the absence of severe calcifications or motion artifacts, MDCT permits noninvasive quantification of coronary stenosis.

Differences Among Cardiologists in Rates of Positive Coronary Angiograms.

BACKGROUND: Understanding the sources of variation for high-cost services has the potential to improve both patient outcomes and value in health care delivery. Nationally, the overall diagnostic yield of coronary angiography is relatively low, suggesting overutilization. Understanding how individual cardiologists request catheterization may suggest opportunities for improving quality and value. We aimed to assess and explain variation in positive angiograms among referring cardiologists. METHODS AND RESULTS: We identified all cases of diagnostic coronary angiography at Massachusetts General Hospital from January 1, 2012, to June 30, 2013. We excluded angiograms for acute coronary syndrome. For each angiogram, we identified clinical features of the patients and characteristics of the requesting cardiologists. We also identified angiogram positivity, defined as at least 1 epicardial coronary stenosis ≥50% luminal narrowing. We then constructed a series of mixed-effects logistic regression models to analyze predictors of positive coronary angiograms. We assessed variation by physician in the models with median odds ratios. Over this time period, 5015 angiograms were identified. We excluded angiograms ordered by cardiologists requesting <10 angiograms. Among the remaining 2925 angiograms, 1450 (49.6%) were positive. Significant predictors of positive angiograms included age, male patients, and peripheral arterial disease. After adjustment for clinical variables only, the median odds ratio was 1.23 (95% CI 1.0-1.36), consistent with only borderline clinical variation after adjustment. In the full clinical and nonclinical model, the median odds ratio was 1.07 (95% CI 1.07-1.20), also consistent with clinically insignificant variation. CONCLUSIONS: Substantial variation exists among requesting cardiologists with respect to positive and negative coronary angiograms. After adjustment for clinical variables, there was only borderline clinically significant variation. These results emphasize the importance of risk adjustment in reporting related to quality and value.

Quantitative parameters of image quality in multidetector spiral computed tomographic coronary imaging with submillimeter collimation.

Multidetector computed tomography (MDCT) permits visualization of the coronary arteries, but limited spatial and temporal resolution can lead to artifacts. We quantitatively evaluated the image quality that can be obtained with the latest generation of MDCT scanners with submillimeter collimation and increased gantry rotation speed. Thirty patients with angiographically proved absence of significant coronary artery stenoses (mean age 56 +/- 13 years, mean heart rate 62 +/- 13 beats/min) were studied by MDCT (12 x 0.75 mm collimation, 420-ms tube rotation, 210-ms temporal resolution, 500 mA, 120 kVp, retrospective electrocardiographic gating). In multiplanar reconstructions of the 4 major coronary arteries (left main, left anterior descending, left circumflex, and right coronary artery), the overall visualized vessel length and the length of segments without motion artifacts were measured. Vessel diameters at 8 predefined locations were measured in MDCT maximum intensity projections and in corresponding invasive angiograms. The mean lengths of visualized coronary arteries were left main 13 +/- 6 mm, left anterior descending 138 +/- 39 mm, left circumflex 84 +/- 34 mm, and right coronary artery 155 +/- 41 mm. On average, 93 +/- 13% of the total visualized vessel length was depicted without motion artifacts (left main 100 +/- 0%, left anterior descending 93 +/- 12%, left circumflex 91 +/- 17%, and right coronary artery 87 +/- 14%). The percentage of vessel length visualized free of motion artifacts was significantly higher in patients with a heart rate 60 beats/min (96 +/- 8% vs 89 +/- 17%, p <0.05). Vessel diameters in MDCT correlated closely to quantitative coronary angiography (R(2) 0.83 to 0.87). In conclusion, MDCT with submillimeter collimation and improved temporal resolution permits reliable visualization of the vessel lumen and accurate measurements of vessel dimensions.

An angiographic and intravascular ultrasound study of the left anterior descending coronary artery in takotsubo cardiomyopathy.

The precise cause of takotsubo cardiomyopathy (TC) remains controversial. Plaque rupture with transient thrombotic occlusion of a transapical left anterior descending coronary artery (LAD) has been advanced as a potential mechanism. To explore this hypothesis, the investigators analyzed data from 11 patients prospectively enrolled in the Rhode Island Takotsubo Cardiomyopathy Registry who underwent coronary angiography and intravascular ultrasound evaluation of the LAD during their initial presentation. Despite the presence of nonobstructive coronary artery disease, no culprit lesion was identified in any patient. Similarly, the course of the LAD failed to account for the characteristic left ventricular apical ballooning seen in TC. In conclusion, an atherosclerotic coronary lesion in the LAD causing an aborted myocardial infarction may not be the primary underlying cause of TC, and nonobstructive coronary artery disease and TC may coexist without a direct causal association.

Comparison of symptoms, treatment, and outcomes of coronary artery disease among rheumatoid arthritis and matched subjects undergoing percutaneous coronary intervention.

OBJECTIVE: Rheumatoid arthritis (RA) is associated with an increased prevalence of coronary artery disease (CAD). We investigated the presenting symptoms of CAD, coronary anatomy (single versus multi-vessel CAD), and treatment among a group of subjects undergoing percutaneous coronary intervention (PCI) with angioplasty and/or stenting. METHODS: We evaluated a retrospective cohort of 43 RA subjects and 43 matched non-RA subjects undergoing PCI at 2 academic referral centers. RA subjects were matched to non-RA subjects on age, gender, history of coronary artery bypass grafting, date of PCI, and interventional cardiologist. We compared cardiac risk factors, presentation, treatment, and outcomes. RESULTS: The mean age of the study cohort was 71 ± 10 years, and the distribution of traditional cardiac risk factors was similar in the subjects with RA compared with the matched non-RA subjects (all P values > 0.05). Seventy-four percent of subjects with RA compared with 67% of those without RA presented with an acute coronary syndrome before PCI (P = 0.48). All subjects in this cohort undergoing PCI had at least 1 stenosis in a major epicardial vessel and similar percentages of subjects with RA (44%) and without RA (40%) had multi-vessel CAD (P = 0.66). The administration of cardiac medications both at PCI and at hospital discharge was not different among subjects with RA compared with matched non-RA subjects. CONCLUSIONS: Among this cohort with significant CAD undergoing PCI, clinical characteristics, presentation, severity of CAD, treatment modalities, and outcomes were similar in subjects with RA and well-matched non-RA subjects.

ST-elevation myocardial infarction mortality in a major academic center "on-" versus "off-" hours.

BACKGROUND: A higher mortality rate for weekend myocardial infarction (MI) admissions has been reported and attributed to the lower availability of primary percutaneous coronary intervention (PCI) during off-hours. However, the data are conflicting and, furthermore, inapplicable to hospitals where primary PCI is invariably performed. METHODS: This study was conducted in a tertiary hospital where primary PCI is routinely performed in all patients with ST-elevation myocardial infarction (STEMI). Patients admitted during on-hours (Monday through Friday 7 am-7 pm) where compared to off-hours patients (including weekends). The primary endpoint of in-hospital mortality, cardiogenic shock and recurrent MI was examined. A second analysis that excluded STEMI transfers, in-hospital mortality and reperfusion times was examined. RESULTS: Between 2003 and 2007, 747 STEMI patients (46% on-hours vs. 56% off-hours) underwent primary PCI. Demographic characteristics were similar between on- and off-hours groups. However, off-hours STEMI admissions had significantly greater in-hospital mortality rates (8% vs. 3.7%; p = 0.01) and higher rates of cardiogenic shock (37% vs. 24%; p = 0.0001). Admission arrival time was an independent predictor of in-hospital mortality (hazard ratio [HR] 3.98, 95% confidence interval [CI] 1.10-14.38; p = 0.035). Longer door-to-balloon times (DTB) were observed during off-hours (134 vs. 109 minutes; p < 0.0001), even after excluding the transfer population (63 vs. 89 minutes; p < 0.0001). CONCLUSION: Higher rates of in-hospital mortality and cardiogenic shock may be expected in STEMI patients admitted during off-hours, even when primary PCI is performed. Longer DTB times during off-hours may partially explain our findings. Strategies to optimize reperfusion time during off-hours, including perhaps a 24/7 in-house "STEMI team" may be necessary.

High-speed rotational atherectomy and coronary stenting: QCA and QCU analysis.

To evaluate the acute effect of pretreatment with high-speed rotational atherectomy (HSRA) on stent deployment (rotastenting), we studied 33 patients with rotastenting of 40 segments, 34 patients with 40 coronary segments treated with Palmaz-Schatz stenting alone, and 34 patients with 40 segments treated with HSRA. The HSRA- and stent-alone patient groups were selected retrospectively by matching the quantitative coronary angiography (QCA) reference diameter (D ref). QCA revealed similar baseline percent of stenosis (85.3% +/- 12.4%), minimal luminal diameter (MLD), and D ref. The percent area expansion was calculated as a ratio between the minimal intrastent area and the reference area measured by intracoronary ultrasound. The rotastent group was characterized by more frequent calcification compared to HSRA and stent groups (67.5% vs. 20% and 12.5%; P < 0.01). Lesion length determined by QCA was longer both in the HSRA and the rotastent groups vs. the stent-alone group (21.1 +/- 12.3 and 20.9 +/- 4.3 vs. 17.0 +/- 7.7 mm; P < 0.05). In this small study, there was no difference demonstrated between final MLD in the rotastent and stent-alone groups. However, a smaller MLD was achieved in the HSRA group (3.0 +/- 0.7 vs. 3.1 +/- 0.5 vs. 2.5 +/- 0.7 mm, respectively; P < 0.01). The degree of stent expansion was higher in the rotastent group compared to the stent-alone group (91.9% +/- 4.4% vs. 79.7% +/- 3.4%; P < 0.03) and the % residual area of plaque was less for the rotastent group than for the stent-alone group (12.1% +/- 13.2% vs. 21.1% +/- 17.5%; P = 0.03). These data suggest that antecedent HSRA atheroma debulking using HSRA results in improved intravascular stent expansion and reduction in residual plaque, facilitating optimal stent deployment.