Pooled diagnostic accuracy of resting distal to aortic coronary pressure referenced to fractional flow reserve: The importance of resting coronary physiology.

INTRODUCTION: Both resting and hyperemic physiologic methods to guide coronary revascularization improve cardiovascular outcomes compared with angiographic guidance alone. Fractional flow reserve (FFR) remains underutilized due to concerns regarding hyperemia, prompting study of resting distal to aortic coronary pressure (Pd/Pa). Pd/Pa is a vasodilator-free resting index unlike FFR. While Pd/Pa is similar to another resting index, instantaneous wave-free ratio (iFR), it is a whole-cycle measurement not limited to the wave-free diastolic period. Pd/Pa is not validated clinically although multiple accuracy studies have been performed. Our meta-analysis examines the overall diagnostic accuracy of Pd/Pa referenced to FFR, the accepted invasive standard of ischemia. METHODS: We searched PubMed, EMBASE, Central, ProQuest, and Web of Science databases for full text articles published through August 9, 2017 addressing the diagnostic accuracy of Pd/Pa referenced to FFR < 0.80. The following keywords were used: "distal coronary artery pressure" OR "Pd/Pa" AND "fractional flow reserve" OR "FFR." RESULTS: In total, 14 studies comprising 7004 lesions were identified. Pooled diagnostic accuracy estimates of Pd/Pa versus FFR < 0.80 were: sensitivity, 0.77 (95% CI, 0.75-0.78); specificity, 0.82 (0.81-0.83); positive likelihood ratio, 4.7 (3.3-6.6); negative likelihood ratio, 0.29 (0.24-0.34); diagnostic odds ratio, 18.1 (14.4-22.6); area under the summary receiver-operating characteristic curve of 0.88; and diagnostic accuracy of 0.80 (0.76-0.83). CONCLUSIONS: Pd/Pa shows adequate agreement with FFR as a resting index of coronary stenosis severity without the undesired effects and cost of hyperemic agents. Pd/Pa has the potential to guide coronary revascularization with easier application and availability compared with iFR and FFR.

The Incidence, Risk Factors, and Chronobiology of Acute Myocardial Infarction Ten Years After Hurricane Katrina.

OBJECTIVE: The purpose of this study was to investigate the 10-year impact of Hurricane Katrina on the incidence of acute myocardial infarction (AMI) along with contributing risk factors and any alteration in chronobiology of AMI. METHODS: A single-center, retrospective, comparison study of AMI incidence was performed at Tulane University Health Sciences Center from 2 years before Hurricane Katrina to 10 years after Hurricane Katrina. A 6-year, pre-Katrina and 10-year, post-Katrina cohort were also compared according to pre-specified demographic, clinical, and chronobiological data. RESULTS: AMI incidence increased from 0.7% (150/21,079) to 2.8% (2,341/84,751) post-Katrina (P<0.001). The post-Katrina cohort had higher rates of coronary artery disease (36.4% vs. 47.9%, P=0.01), diabetes mellitus (31.3% vs. 39.9%, P=0.04), hyperlipidemia (45.4% vs. 59.3%, P=0.005), smoking (34.4% vs. 53.8%, P<0.001), drug abuse (10.2% vs. 15.4%, P=0.02), psychiatric illness (6.7% vs. 14.9%, P<0.001), medication non-adherence (7.3% vs. 15.3%, P<0.001), and lack of employment (7.2% vs. 16.4%, P<0.001). The post-Katrina group had increased rates of AMI during nights (29.8% vs. 47.8%, P<0.001) and weekends (16.1% vs. 29.1%, P<0.001). CONCLUSIONS: Even 10 years after the storm, Hurricane Katrina continues to be associated with increased incidence of AMI, higher prevalence of traditional cardiovascular and psychosocial risk factors, and an altered chronobiology of AMI toward nights and weekends. (Disaster Med Public Health Preparedness. 2019;13:217-222).

Instantaneous wave-free ratio as an alternative to fractional flow reserve in assessment of moderate coronary stenoses: A meta-analysis of diagnostic accuracy studies.

BACKGROUND/PURPOSE: Fractional flow reserve (FFR) remains underutilized due to practical concerns related to the need for hyperemic agents. These concerns have prompted the study of instantaneous wave-free ratio (iFR), a vasodilator-free index of coronary stenosis. Non-inferior cardiovascular outcomes have been demonstrated in two recent randomized clinic trials. We performed this meta-analysis to provide a necessary update of the diagnostic accuracy of iFR referenced to FFR based on the addition of eight more recent studies and 3727 more lesions. METHODS: We searched the PubMed, EMBASE, Central, ProQuest, and Web of Science databases for full text articles published through May 31, 2017 to identify studies addressing the diagnostic accuracy of iFR referenced to FFR≤0.80. The following keywords were used: "instantaneous wave-free ratio" OR "iFR" AND "fractional flow reserve" OR "FFR." RESULTS: In total, 16 studies comprising 5756 lesions were identified. Pooled diagnostic accuracy estimates of iFR versus FFR≤0.80 were: sensitivity, 0.78 (95% CI, 0.76-0.79); specificity, 0.83 (0.81-0.84); positive likelihood ratio, 4.54 (3.85-5.35); negative likelihood ratio, 0.28 (0.24-0.32); diagnostic odds ratio, 17.38 (14.16-21.34); area under the summary receiver-operating characteristic curve, 0.87; and an overall diagnostic accuracy of 0.81 (0.78-0.84). CONCLUSIONS: In conclusion, iFR showed excellent agreement with FFR as a resting index of coronary stenosis severity without the undesired effects and cost of hyperemic agents. When considering along with its clinical outcome data and ease of application, the diagnostic accuracy of iFR supports its use as a suitable alternative to FFR for physiology-guided revascularization of moderate coronary stenoses. SUMMARY: We performed a meta-analysis of the diagnostic accuracy of iFR referenced to FFR. iFR showed excellent agreement with FFR as a resting index of coronary stenosis severity without the undesired effects and cost of hyperemic agents. This supports its use as a suitable alternative to FFR for physiology-guided revascularization of moderate coronary stenoses.

Physiologic assessment of moderate coronary lesions: a step towards complete revascularization in coronary artery bypass grafting.

BACKGROUND: An accurate diagnostic assessment of coronary artery disease is crucial for patients undergoing coronary artery bypass grafting (CABG). Fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) to guide complete revascularization have not been adequately studied in patients prior to CABG. We compared an anatomic to a physiologic assessment of moderate coronary lesions (40-70% stenosis) in patients referred for CABG. METHODS: We retrospectively reviewed 109 medical records of patients who underwent CABG at Tulane Medical Center from 2014 to 2016. Patients were divided into an FFR/iFR-guided and an angiography-guided group. Clinical characteristics, procedural outcomes, and clinical outcomes for the two groups were compared over an 18-month follow-up period. RESULTS: There were significantly higher rates of three-vessel anastomoses (85.7% vs. 74.7%, P<0.05) and venous grafting (85.7% vs. 76.8%, P<0.05) in the FFR/iFR group. The FFR/iFR group had a lower rate of grafts placed to the left anterior descending artery (LAD) distribution than the angiography group (7.1% vs. 29.5%, P<0.05). The FFR/iFR group had a higher rate of grafts placed to the left circumflex (LCx) artery distribution than the angiography group (28.6% vs. 9.5%, P<0.05). We observed a trend toward reduction in major adverse cardiac events (MACEs) (7.1% vs. 11.6%, P=0.369) and angina (0.0% vs. 6.3%, P=0.429) in the FFR/iFR group compared to the angiography group over 18 months. CONCLUSIONS: Physiologic assessment of coronary lesions can effectively guide complete revascularization in patients undergoing CABG. Moreover, FFR/iFR-guided CABG was associated with significantly higher rates of three-vessel anastomoses, venous grafting, and graft distribution to the circumflex system.

Outcomes after the palliative arterial switch operation in neonates with single-ventricle anatomy.

BACKGROUND: Newborns with single-ventricle anatomy, transposition of the great arteries, and systemic outflow obstruction are challenging patients most often managed with a Norwood or Damus-Kaye-Stansel (DKS) procedure. The palliative arterial switch operation (pASO) offers the theoretical advantage of avoiding a systemic-to-pulmonary artery shunt physiology and posterior entrapment of the left pulmonary artery while aligning the single left ventricle with the posterior semilunar valve. Limited outcome data exist for the pASO. The purpose of this study was to examine the clinical course of patients after this operation. METHODS: We conducted a retrospective review of all neonates undergoing a pASO at our institution from July 1995 to June 2011. RESULTS: Fourteen patients underwent pASO at a median age of 7 days (2-16 days). Primary diagnoses included double-inlet left ventricle (6 patients [43%]), tricuspid atresia (TA) (4 patients [29%]), and other (4 patients [29%]). Concomitant procedures at initial operation included aortic arch reconstruction (13 patients [93%]), pulmonary artery banding (6 patients [43%]), and placement of a systemic-to-pulmonary artery shunt (1 patient [7%]). Median intensive care unit stay and hospital length of stay were 11 days (4-60 days) and 21 days (9-84), respectively. There were no deaths. All patients had advanced to a bidirectional cavopulmonary shunt (BCPS). Four patients required intervention between the pASO and BCPS procedures: systemic-to-pulmonary artery shunt (3 patients [21%]) and pulmonary artery banding revision (1 patient [7%]). Eleven patients had Fontan completion; the remaining 3 patients are candidates for this procedure. At the time of the Fontan operation, 7 (64%) patients required pulmonary artery augmentation. All patients were alive at last follow-up (median, 5 years [3 months-14 years]). At last echocardiographic follow-up (median, 5 years [3 months-10 years]), all patients had normal ventricular function, trivial to mild neoaortic insufficiency, and no left ventricular outflow obstruction. CONCLUSIONS: The pASO should be considered in neonates with single ventricle, transposition, and systemic outflow obstruction because it affords a favorable anatomic arrangement for long-term palliation, with excellent survival and preserved ventricular function.