Exhaustion of coronary vasodilatory reserve in the resting state: Clinical characteristics and long-term outcomes after intervention.

OBJECTIVES/BACKGROUND: Resting coronary blood flow approximates flow with maximal vasodilation in very severe coronary stenosis. We studied the incidence of exhausted vasodilatory reserve by FFR, its clinical characteristics and long-term prognosis after FFR guided percutaneous coronary intervention (PCI). METHODS: Consecutive patients undergoing FFR-guided PCI for coronary stenosis with reduced resting blood flow (baseline Pd/Pa < 0.8) were included. Basal maximal vasodilation (BMV) was defined as less than 5% difference between resting Pd/Pa and FFR, that is, FFR-baseline Pd/Pa < 0.05. RESULTS: Of 658 vessels that underwent FFR-guided PCI in 602 patients, 151 vessels had resting blood flow in the ischemic range (baseline Pd/Pa ≤ 0.8) and were included in the analysis. Of these, 28 lesions in 28 patients met criteria for BMV (4.25% of the entire registry and 18.5% of those with the reduced basal coronary flow). Stenosis severity was a significant predictor of the presence of BMV. In long term follow-up (median 106 ± 3.6 months), BMV was not associated with increased target vessel revascularization (TVR) or major adverse cardiac event compared to non-BMV(OR 1.9, 95% CI 0.7-4.8, p-value 0.2 and OR 1.3, 95% CI 0.75-2.5, p = 0.3, respectively). CONCLUSION: Low baseline Pd/Pa that approximates fractional flow reserve (exhausted vasodilatory reserve) defines a subgroup of patients with severe coronary artery stenosis. Prognosis, when treated with PCI along with medical therapy, appears similar to those with intact vasodilatory reserve.

Prospective Evaluation of the Strategy of Functionally Optimized Coronary Intervention.

Background Long-term outcomes after percutaneous coronary intervention (PCI) relate in part to residual ischemia in the treated vessel, as reflected by post-PCI fractional flow reserve (FFR). The strategy of FFR after PCI and treatment of residual ischemia-known as functionally optimized coronary intervention (FCI)-may be feasible and capable of improving outcomes. Methods and Results Feasibility and results of FCI using an optical-sensor pressure wire were prospectively evaluated in an all-comer population with 50% to 99% lesions and ischemic FFR (≤0.80; ClinicalTrials.gov identifier NCT03227588). FCI was attempted in 250 vessels in 226 consecutive patients. The PCI success rate was 99.6% (249/250 vessels). FCI technical success-that is, FFR before and after PCI and PCI itself using the FFR wire-was 92% (230/250 vessels). Incidence of residual ischemia in the treated vessel was 36.5%. Approximately a third of these vessels (34.5%, n=29) were considered appropriate for further intervention, with FFR increasing from 0.71±0.07 to 0.81±0.06 (P<0.001). Pressure wire pullback showed FFR ≤0.8 at distal stent edge was 7.9% and 0.7% proximal to the stent. FFR increase across the stent was larger in the ischemic than in the nonischemic group (0.06 [interquartile range: 0.04-0.08] versus 0.03 [interquartile range: 0.01-0.05]; P<0.0001) compatible with stent underexpansion as a contributor to residual ischemia. Conclusions FCI is a feasible and safe clinical strategy that identifies residual ischemia in a large proportion of patients undergoing angiographically successful PCI. Further intervention can improve ischemia. The impact of this strategy on long-term outcomes needs further study.

Distal Versus Conventional Transradial Artery Access for Coronary Angiography and Intervention: A Meta-Analysis.

BACKGROUND: Distal transradial artery access (dTRA) through the anatomical snuffbox is a novel approach for performing coronary angiography and interventions. However, the safety and efficacy of dTRA as compared to conventional TRA (cTRA) remains unknown. We aim to evaluate the outcomes of dTRA versus cTRA for coronary angiography and intervention. METHODS: Electronic search of the National Library of Medicine PubMed and Cochrane Library databases was performed until April 2019 for studies comparing the clinical outcomes of dTRA approach versus conventional TRA (cTRA) approach in coronary angiography and interventions. Random-effects DerSimonian-Laird risk ratios (RR) were calculated. The main outcome was failure of access site utilization. Other outcomes included access site hematoma, radial artery spasm, dissection, and occlusion. RESULTS: Five studies (4 observational and 1 randomized controlled) with a total of 6746 patients (dTRA n = 3209 and cTRA n = 3537) were available for analysis. The failure rate was similar in dTRA and cTRA groups (5.26% versus 3.75%; RR = 1.36; 95%CI 0.41-4.48; p = 0.62). Similarly, no difference was observed between dTRA and cTRA in regards to access site hematoma (1.20% versus 1.24%, RR = 1.01; 95%CI 0.49-2.07; p = 0.99), radial artery spasm (1.42 versus 3.84%, RR = 0.91; 95%CI 0.32-2.62; p = 0.86), or radial artery dissection (0.11 versus 0.20%, RR = 0.63; 95%CI 0.18-2.16; p = 0.46). The rate of radial artery occlusion was lower with dTRA (2.30 versus 4.86%, RR = 0.51; 95%CI 0.32-0.81; p = 0.004) as compared to cTRA. CONCLUSION: Distal TRA appears to be a safe and effective alternative to conventional TRA. The outcomes of this novel technique warrant further randomized studies.

Reasons of refusal and drop out in a follow up study involving primigravidae in Pakistan.

OBJECTIVE: To determine the reasons underlying the refusals to participate and drop outs from a follow up study involving primigravidae. DESIGN: A descriptive study. METHODS: Aga Khan University and Aga Khan Hospital for Women, Karachi, jointly initiated a nested case-control study on primigravidae for determining the predictability of preeclampsia using various biochemical markers in blood. The protocol-eligible study subjects were counseled along with their accompanying family members to participate in the study. All women recruited in this study were followed up throughout their pregnancy till delivery. RESULTS: One thousand six hundred and sixty-five primigravidae were identified as the potential study subjects. Out of which, 1,307 (78.5%) consented and 358 (21.5%) refused to participate in the study. The most common reason underlying the refusal was inability to get permission from the family members (n=84; 34.4%) followed by fear of prick (n=51; 20.9%). For 114 refusals, either the reason was not mentioned by the counseled women (n=60) or the data was missing (n=54). Out of 1,307 women recruited in the research, only 611 (46.7%) women completed the study according to the prescribed protocol. Among the rest, 102 (7.8%) subsequently withdrew from the research, 503 (38.5%) were dropped out, and 91 (7.0%) were lost to follow up. CONCLUSIONS: Refusal to participate and drop out from the research program are two significant factors hindering the smooth flow of a study. In Pakistan, the major reason for the refusal by the protocol-eligible pregnant women for participating in a research program is the unwillingness of the family members.

Prolonged Balloon Inflation to Effect Full Stent Expansion in Critical CAD During Left Ventricular Support.

The extent to which a stent is expanded is a primary factor in determining both short- and long-term outcomes during percutaneous coronary intervention (PCI). This paper presents the first case of prolonged balloon inflation using the pressure optimization protocol allowing full stent expansion during PCI of critical coronary artery disease with severely reduced ejection fraction using the Impella. (Level of Difficulty: Intermediate.).

Acute Influenza Infection Presenting with Cardiac Tamponade: A Case Report and Review of Literature.

INTRODUCTION: Cardiac complications associated with influenza infection can occur either via a direct effect of the virus on the heart or through exacerbation of preexisting cardiovascular disease. We present a case of a 57-year-old man with acute influenza infection complicated by pericardial effusion and cardiac tamponade. CASE PRESENTATION: A 57-year-old white man presented to the Emergency Department with sudden onset of severe, nonexertional, retrosternal, pressure-like chest pain for a few hours and with fever and muscle aches for 2 days. The patient was initially admitted because of suspected acute coronary syndrome. The next morning, he complained of acute-onset shortness of breath and had hypotension and tachycardia. On examination, his peripheral extremities were cold and heart sounds were distant. Pulsus paradoxus was 20 mmHg. The electrocardiogram showed low-voltage QRS complex with electrical alternans. An urgently performed bedside echocardiogram showed moderate pericardial effusion with a small right ventricular cavity with diastolic collapse. Emergent pericardiocentesis was performed, with removal of 250 mL of fluid from the pericardial space. The patient's hemodynamic status immediately improved. Analyses of pericardial fluid demonstrated no bacteria, acid-fast bacilli, or malignant cells. The result of a rapid influenza diagnostic test with polymerase chain reaction was positive for influenza A virus, with other viral panels yielding normal results. The patient was treated with oseltamivir for 5 days. DISCUSSION: Pericardial involvement is a rare and perhaps underreported complication of influenza infection. Early recognition of cardiac symptoms and appropriate diagnostic workup in a patient presenting with influenza-like symptoms is important to avoid life-threatening complications.

Hepatic stiffness in the bidirectional cavopulmonary circulation: The Liver Adult-Pediatric-Congenital-Heart-Disease Dysfunction Study group.

OBJECTIVES: We hypothesized that hepatic injury in single-ventricle CHD has origins that predate the Fontan operation. We aimed to measure hepatic stiffness using ultrasound and shear wave elastography (SWE) in a bidirectional cavopulmonary connection (BCPC) cohort. METHODS: Subjects were prospectively recruited for real-time, hepatic, ultrasound-SWE for hepatic stiffness (kPa) and echocardiography. Doppler velocities, a velocity-time integral, flow volume, and resistive index, pulsatility index, and acceleration index were measured in celiac and superior mesenteric arteries, and in the main portal vein (MPV). Comparisons were made among subjects who had BCPC, subjects who were healthy, and a cohort of patients who had undergone the Fontan procedure. RESULTS: Forty subjects (20 patients who had BCPC; 20 age- and gender-matched control subjects) were studied. The hepatic stiffness in BCPC was elevated, compared with that in control subjects (7.2 vs 5.7 kPa; P = .039). Patients who had BCPC had significantly higher celiac artery resistive index (0.9 vs 0.8; P = .002); pulsatility index (2.2 vs 1.7; P = .002); and systolic-diastolic flow ratio (10.1 vs 5.9; P = .002), whereas the superior mesenteric artery acceleration index (796 vs 1419 mL/min in control subjects; P = .04) was lower. An elevated resistive index (0.42 vs 0.29; P = .002) and pulsatility index (0.55 vs 0.35; P = .001) were seen in MPV, whereas MPV flow was reduced (137.3 vs 215.7 mL/min in control subjects; P = .036). A significant correlation was found for hepatic stiffness with right atrial pressure obtained at catheterization (P = .002). Comparison with patients who underwent the Fontan procedure showed patients who had BCPC had lower hepatic stiffness (7.2 vs 15.6 kPa; P < .001). CONCLUSIONS: Hepatic stiffness is increased with BCPC physiology, and this finding raises concerns that hepatopathology in palliated, single-ventricle CHD is not exclusively attributable to Fontan physiology. Hepatic stiffness measurements using SWE are feasible in this young population, and the technique shows promise as a means for monitoring disease progression.

Echocardiographic measurement methods for left ventricular linear dimensions in children result in predictable variations in results.

Precise quantification of left ventricular (LV) cavity dimensions assumes great importance in clinical cardiology. Pediatric guidelines recommend the left parasternal short axis (PSA) imaging plane for measuring LV cavity dimensions, while measuring from the long axis (PLA) plane is the convention in adult echocardiography. We sought to compare measurements obtained by two-dimensional (2D) and M-mode (MM) techniques in the two imaging planes. Healthy subjects were prospectively recruited for research echocardiography. Complete 2D, spectral and color flow Doppler examinations were performed in a non-sedated state. All subjects had structurally and functionally normal hearts. LV cavity dimensions were obtained in PLA and PSA views using 2D and MM yielding four measurement sets for each subject: PLA direct 2D; PLA 2D-guided MM, PSA direct 2D, PSA 2D-guided MM. A commercially available ultrasound system (Vivid E9, GE) was used and data stored digitally for subsequent analysis (EchoPAC BT11, GE). Acquisition and measurements were made by a single observer from at least three consecutive cardiac cycles, and averaged for each of the four categories. The study cohort consisted of 114 subjects (mean age 9 years, range 1-18; mean BSA 1.1 m(2), range 0.42-2.6). The smallest estimate of LV end-diastolic dimension (LVED) was obtained by PLA 2D, with larger estimates by PLA MM, PSA 2D, and PSA MM. Largest estimates of LV end-systolic dimension (LVES) are by 2D methods, with smaller estimates by both MM techniques. The smallest shortening fraction (SF) was by PLA 2D; other methods yielded larger SF. Temporal resolution is limited in 2D methodology and may account for the smaller LVED, larger LVES and smaller SF observed. Long axis methodology may predispose to off-center or non-perpendicular data acquisition and the potential for dimensional underestimation, particularly in diastole. Consistency in method for assessment of LV dimensions in children is an important factor for serial comparisons.

Systemic venous diameters, collapsibility indices, and right atrial measurements in normal pediatric subjects.

BACKGROUND: Compromise of right heart function is an important feature of many forms of congenital heart disease, and right atrial (RA) pressure is clinically relevant. Inferior vena cava (IVC) diameter and inspiratory collapse are indices of RA pressure, but pediatric data are lacking. METHODS: RA measurements, systemic venous diameters, and Doppler filling fractions were prospectively investigated in healthy volunteer children and adolescents. The IVC was measured in its long axis just above the junction with the hepatic veins in the subxiphoid view and the superior vena cava at its junction with the right atrium in the right parasternal view. The changes in IVC diameter (IVCD) during quiet respiration and with a sniff were recorded. Hepatic venous systolic filling fraction was calculated from Doppler velocities in the first hepatic vein. RA major-axis length, area, and volume were measured from the apical four-chamber view. Three measurements of each parameter were averaged over at least three respiratory cycles. The IVC collapsibility index (IVCCI) was calculated as [(IVCDmax - IVCDmin)/IVCDmax] × 100. Substituting IVCDsniff for IVCDmin in the formula, the IVCCIsniff was calculated. RESULTS: Of 132 subjects enrolled, data in 120 (mean age, 8.3 ± 4.5 years) were analyzed. The maximal (expiratory) and minimal (inspiratory) diameters during free breathing were 12.1 ± 3.8 and 8.9 ± 3.8 mm for the IVC and 11.9 ± 3.4 and 7.9 ± 2.6 mm for the superior vena cava. IVCCImin and IVCCIsniff were 30 ± 13 and 47 ± 18, respectively. The RA major-axis length, area, and indexed maximal volume were 3.7 ± 0.7 cm, 10.3 ± 3.6 cm(2), and 22.3 ± 7.0 mL/m(2), respectively. Correlations of maximal superior vena cava and IVC dimensions with body surface area were slightly better than with age and much stronger than with RA volume. No significant correlation was found between IVCCIs and age, gender, or indexed RA volume. CONCLUSIONS: Measurement of systemic venous diameters, collapsibility indices, and RA volumes is feasible in healthy children and adolescents. Venous diameters increase predictably with growth and so must be interpreted in light of body surface area. IVCCIs and hepatic venous filling fraction compare closely with those reported in adults. Pediatric nomograms for these parameters are provided, and they should next be evaluated for relation to directly measured RA pressure in this age group.