The WOEST 2 registry : A prospective registry on antithrombotic therapy in atrial fibrillation patients undergoing percutaneous coronary intervention.

BACKGROUND: Patients on oral anticoagulants (OACs) undergoing percutaneous coronary intervention (PCI) also require aspirin and a P2Y12 inhibitor (triple therapy). However, triple therapy increases bleeding. The use of non-vitamin K antagonist oral anticoagulants (NOACs) and stronger P2Y12 inhibitors has increased. The aim of our study was to gain insight into antithrombotic management over time. METHODS: A prospective cohort study of patients on OACs for atrial fibrillation or a mechanical heart valve undergoing PCI was performed. Thrombotic outcomes were myocardial infarction, stroke, target-vessel revascularisation and all-cause mortality. Bleeding outcome was any bleeding. We report the 30-day outcome. RESULTS: The mean age of the 758 patients was 73.5 ± 8.2 years. The CHA2DS2-VASc score was ≥ 3 in 82% and the HAS-BLED score ≥ 3 in 44%. At discharge, 47% were on vitamin K antagonists (VKAs), 52% on NOACs, 43% on triple therapy and 54% on dual therapy. Treatment with a NOAC plus clopidogrel increased from 14% in 2014 to 67% in 2019. The rate of thrombotic (4.5% vs 2.0%, p = 0.06) and bleeding (17% vs. 14%, p = 0.42) events was not significantly different in patients on VKAs versus NOACs. Also, the rate of thrombotic (2.9% vs 3.4%, p = 0.83) and bleeding (18% vs 14%, p = 0.26) events did not differ significantly between patients on triple versus dual therapy. CONCLUSIONS: Patients on combined oral anticoagulation and antiplatelet therapy undergoing PCI are elderly and have both a high bleeding and ischaemic risk. Over time, a NOAC plus clopidogrel became the preferred treatment. The rate of thrombotic and bleeding events was not significantly different between patients on triple or dual therapy or between those on VKAs versus NOACs.

Optimization in First-Passage Resetting.

We investigate classic diffusion with the added feature that a diffusing particle is reset to its starting point each time the particle reaches a specified threshold. In an infinite domain, this process is nonstationary and its probability distribution exhibits rich features. In a finite domain, we define a nontrivial optimization in which a cost is incurred whenever the particle is reset and a reward is obtained while the particle stays near the reset point. We derive the condition to optimize the net gain in this system, namely, the reward minus the cost.

Effective radiation doses associated with non-invasive versus invasive assessment of coronary anatomy and physiology.

OBJECTIVES: To compare the effective radiation dose (ERD) needed to obtain information on coronary anatomy and physiology by a non-invasive versus an invasive diagnostic strategy. BACKGROUND: Knowledge of anatomy and physiology is needed for management of patients with coronary artery disease (CAD). There is, however, a growing concern about detrimental long-term effects of radiation associated with diagnostic procedures. METHODS: In a total of 671 patients with suspected CAD, we compared the ERD needed to obtain anatomical and physiological information through a non-invasive strategy or an invasive strategy. The non-invasive strategy consisted of coronary computed tomography angiography (CCTA) and single photon emission computed tomography (SPECT). The invasive strategy included coronary angiography (CA) and fractional flow reserve (FFR) measurement. In 464 patients, the data were acquired in Period 2009 and in 207 the data were acquired in Period 2011 (after each period, the CCTA- and the CA-equipment had been upgraded). RESULTS: For the Period 2009 total ERD of the non-invasive approach was significantly larger compared to the invasive approach (28.45 ± 5.37 mSv versus 15.79 ± 7.95 mSv, respectively; P < 0.0001). For Period 2011, despite the significant decrease in ERD for both groups (P<0.0001 for both), the ERD remained higher for the non-invasive approach compared to the invasive approach (16.67 ± 10.45 mSv vs. 10.36 ± 5.87 mSv, respectively; P < 0.0001). Simulation of various diagnostic scenarios showed cumulative radiation dose is the lowest when a first positive test is followed by an invasive strategy. CONCLUSION: To obtain anatomic and physiologic information in patients with suspected CAD, the combination of CA and FFR is associated with lower ERD than the combination of CCTA and SPECT.

Physiological and angiographic outcomes of PCI in calcified lesions after rotational atherectomy or intravascular lithotripsy.

BACKGROUND: Percutaneous coronary interventions (PCI) in calcified coronary artery lesions are associated with impaired stent expansion, higher rate of periprocedural complications and cardiac mortality. Lesion preparation using calcium modifying techniques such as Rotational Atherectomy (RA) or Intravascular Lithotripsy (IVL) has been advocated. Studies comparing these technologies are lacking. We aimed to compare in-stent pressure gradients, evaluated by vessel fractional flow reserve (vFFR), in calcific lesions treated using either RA or IVL. METHODS: Patients undergoing either RA- or IVL-assisted PCI from two European centers were included. Propensity score matching (1:2) was performed to control for potential bias. Primary outcome was post-PCI in-stent pressure gradients calculated by vFFR (vFFRgrad). Secondary outcomes included the proportion of patients with complete functional revascularization defined as distal vFFR post-PCI (vFFRpost) ≥ 0.90. RESULTS: From a cohort of 210 patients, 105 matched patients (70 RA and 35 IVL) were included. Pre-PCI vFFR did not differ between groups (0.65 ± 0.13 RA and 0.67 ± 0.11 IVL). After PCI, in-stent pressure gradients were significantly lower in the IVL group (0.032 ± 0.026 vs 0.043 ± 0.026 in the RA group, p = 0.024). The proportions of vessels with functional complete revascularization was similar between the two groups (32.9% vs. 37.1% in the RA and IVL group, respectively; p = 0.669). CONCLUSIONS: Calcific lesions preparation with IVL is effective and resulted in lower in-stent pressure gradients compared to RA. Approximately one third of the patients undergoing PCI for a severely calcified lesion achieved functional revascularization with no difference between rotational RA and IVL.

Quantification of calcium burden by coronary CT angiography compared to optical coherence tomography.

Coronary artery calcifications (CAC) are frequently observed in patients referred for coronary CT angiography (CTA). Calcification volume (in mm3) can accurately be assessed during catheterization by optical coherence tomography (OCT). The aim of the present study was to investigate the accuracy of CTA-derived assessment of calcification volume as compared with OCT. 66 calcified plaques (32 vessels) from 31 patients undergoing OCT-guided PCI with coronary CT acquired as a standard of care were included. Coronary CT and OCT images were matched using fiduciary points. Calcified plaques were reconstructed in three dimensions to calculate calcium volume. A Passing-Bablok regression analysis and the Bland-Altman method were used to assess the agreement between imaging modalities. Twenty-seven left anterior descending arteries and 5 right coronary arteries were analyzed. Median calcium volume by CTA and OCT were 18.23 mm3 [IQR 8.09, 36.48] and 10.03 mm3 [IQR 3.6, 22.88] respectively; the Passing-Bablok analysis showed a proportional without a systematic difference (Coefficient A 0.08, 95% CI - 1.37 to 1.21, Coefficient B 1.61, 95% CI 1.45 to 1.84) and the mean difference was 9.69 mm3 (LOA - 10.2 to 29.6 mm3). No differences were observed for minimal lumen area (Coefficient A 0.07, 95% CI - 0.46 to 0.15, Coefficient B 0.85, 95% CI 0.64 to 1.2). CTA volumetric calcium evaluation overestimates calcium volume by 60% compared to OCT. This may allow for an appropriate interpretation of calcific burden in the non-invasive setting. Even in presence of calcific plaques, a good agreement in the MLA assessment was found. Coronary CT may emerge as a tool to quantify calcium burden for invasive procedural planning.

Effects of dobutamine on coronary stenosis physiology and morphology: comparison with intracoronary adenosine.

BACKGROUND: The mechanisms leading to dobutamine-induced ischemia are not fully understood. In the present study, we investigated the effects of high-dose intravenous dobutamine on morphological and physiological indexes of coronary stenoses. METHODS AND RESULTS: Twenty-two patients with normal left ventricular function and isolated coronary stenoses were studied. At catheterization, mean aortic pressure (P(a)), mean distal coronary pressure (P(d)), and P(d)/P(a) as an index of myocardial resistance were recorded at rest, after intracoronary adenosine, and during intravenous infusion of dobutamine (10 to 40 micrograms . kg(-1). min(-1)). Reference vessel diameter and minimal luminal diameter, as assessed by coronary angiography, did not change during dobutamine infusion compared with baseline (2.84+/-0.49 versus 2.77+/-0.41 mm and 1.35+/-0.38 versus 1. 27+/-0.31 mm, respectively; both P=NS). During peak dobutamine infusion, P(d) and P(d)/P(a) reached similar levels as during adenosine infusion (60+/-18 versus 59+/-18 mm Hg and 0.68+/-0.18 versus 0.68+/-0.17, respectively; all P=NS). In 9 patients, an additional bolus of intracoronary adenosine given at the peak dose of dobutamine failed to further decrease P(d)/P(a). Furthermore, in patients with dobutamine-induced wall motion abnormalities, the maximal decrease in P(d)/P(a) was similar during dobutamine and adenosine infusions. CONCLUSIONS: High-dose intravenous infusion of dobutamine does not modify the dimensions of the epicardial coronary stenosis. However, much like the direct coronary vasodilator adenosine, dobutamine fully exhausts myocardial resistance regardless of the presence of mechanical dysfunction.

Coronary thermodilution to assess flow reserve: experimental validation.

BACKGROUND: Fractional flow reserve (FFR) and coronary flow reserve (CFR) are indices of coronary stenosis severity that provide the clinician with complementary information on the contribution of epicardial arteries and microcirculation to total resistance to myocardial blood flow. At present, FFR and CFR can only be obtained by 2 separate guidewires. The present study tested the validity of the thermodilution principle in assessing CFR with one pressure-temperature sensor-tipped guidewire. METHODS AND RESULTS: In an in vitro model, absolute flow was compared with the inverse mean transit time (1/T(mn)) of a thermodilution curve obtained after a bolus injection of 3 mL of saline at room temperature. A very close correlation (r>0.95) was found between absolute flow and 1/T(mn) when the sensor was placed >/=6 cm from the injection site. In 6 chronically instrumented dogs (60 stenoses; FFR from 0.19 to 0.98), a significant linear relation was found between flow velocity and 1/T(mn). A significant correlation was found between CFR(Doppler), which was calculated from the ratio of hyperemic to resting flow velocities, and CFR(thermo), which was calculated from the ratio of resting to hyperemic T(mn) (r=0.76; SEE=0.24; P<0.001). CONCLUSION: The present findings demonstrate the validity of the thermodilution principle to assess CFR. Because the pressure-temperature sensor was mounted in a commercially available angioplasty guidewire, this technique permits simultaneous measurements of CFR and FFR.

Pressure-derived fractional flow reserve to assess serial epicardial stenoses: theoretical basis and animal validation.

Background-Fractional flow reserve (FFR) is an index of stenosis severity validated for isolated stenoses. This study develops the theoretical basis and experimentally validates equations for predicting FFR of sequential stenoses separately. Methods and Results-For 2 stenoses in series, equations were derived to predict FFR (FFR(pred)) of each stenosis separately (ie, as if the other one were removed) from arterial pressure (P(a)), pressure between the 2 stenoses (P(m)), distal coronary pressure (P(d)), and coronary occlusive pressure (P(w)). In 5 dogs with 2 stenoses of varying severity in the left circumflex coronary artery, FFR(pred) was compared with FFR(app) (ratio of the pressure just distal to that just proximal to each stenoses) and to FFR(true) (ratio of the pressures distal to proximal to each stenosis but after removal of the other one) in case of fixed distal and varying proximal stenoses (n=15) and in case of fixed proximal and varying distal stenoses (n=20). The overestimation of FFR(true) by FFR(app) was larger than that of FFR(true) by FFR(pred) (0.070+/-0.007 versus 0.029+/-0.004, P<0.01 for fixed distal stenoses, and 0.114+/-0.01 versus 0.036+/-0. 004, P<0.01 for fixed proximal stenoses). This overestimation of FFR(true) by FFR(app) was larger for fixed proximal than for fixed distal stenoses. Conclusions-The interaction between 2 stenoses is such that FFR of each lesion separately cannot be calculated by the equation for isolated stenoses (P(d)/P(a) during hyperemia) applied to each separately but can be predicted by more complete equations taking into account P(a), P(m), P(d), and P(w).

Fractional flow reserve in patients with prior myocardial infarction.

BACKGROUND: Fractional flow reserve (FFR), an index of coronary stenosis severity, can be calculated from the ratio of hyperemic distal to proximal coronary pressure. An FFR value of 0.75 can distinguish patients with normal and abnormal noninvasive stress testing in case of normal left ventricular function. The present study aimed at investigating the value of FFR in patients with a prior myocardial infarction. Methods and Results-- In 57 patients who had sustained a myocardial infarction >/=6 days earlier, myocardial perfusion single photon emission scintigraphy (SPECT) imaging and FFR were obtained before and after angioplasty. The sensitivity and specificity of the 0.75 value of FFR to detect flow maldistribution at SPECT imaging were 82% and 87%. The concordance between the FFR and SPECT imaging was 85% (P<0.001). When only truly positive and truly negative SPECT imaging were considered, the corresponding values were 87%, 100%, and 94% (P<0.001). Patients with positive SPECT imaging before angioplasty had a significantly lower FFR than patients with negative SPECT imaging (0.52+/-0.18 versus 0.67+/-0.16, P=0.0079) but a significantly higher left ventricular ejection fraction (63+/-10% versus 52+/-10%, P=0.0009) despite a similar degree of diameter stenosis (67+/-13% versus 68+/-16%, P=NS). A significant inverse correlation was found between LVEF and FFR (R=0.29, P=0.049). CONCLUSIONS: The present data indicate (1) that the 0.75 cutoff value of FFR to distinguish patients with positive from patients with negative SPECT imaging is valid after a myocardial infarction and (2) that for a similar degree of stenosis, the value of FFR depends on the mass of viable myocardium.

Coronary pressure measurement to assess the hemodynamic significance of serial stenoses within one coronary artery: validation in humans.

BACKGROUND: When several stenoses are present within 1 coronary artery, the hemodynamic significance of each stenosis is influenced by the presence of the other(s), and the calculation of coronary and fractional flow reserve (CFR and FFR) for each individual stenosis is confounded. Recently, we developed and experimentally validated a method to determine the true FFR of each stenosis as it would be after the removal of the other stenosis; the true FFR can be reliably predicted by coronary pressures measured before treatment at specific locations within the coronary artery using equations accounting for stenosis interaction. The aim of the present study was to test the validity of these equations in humans. METHODS AND RESULTS: In this study of 32 patients with 2 serial stenoses in 1 coronary artery, relevant pressures were measured before the intervention, after the treatment of 1 stenosis, and after the treatment of both stenoses. The true FFR of each stenosis (FFR(true)) was directly measured after the elimination of the other stenosis and compared with the value predicted (FFR(pred)) from the initial pressure measurements before treatment. Although the hyperemic gradient across 1 stenosis increased significantly (from 10+/-7 to 19+/-11 mm Hg after treatment of the other stenosis), FFR(pred) was close to FFR(true) in all patients (0.78+/-0.12 versus 0.78+/-0.11 mm Hg; r=0.92; Delta%=4+/-0%). Without accounting for stenosis interaction, the value of FFR for each stenosis would have been significantly overestimated (0.85+/-0.08; P:<0.01). CONCLUSIONS: Coronary pressure measurements made by a pressure wire at maximum hyperemia provide a simple, practical method for assessing the individual hemodynamic significance of multiple stenoses within the same artery.

Abnormal epicardial coronary resistance in patients with diffuse atherosclerosis but "Normal" coronary angiography.

BACKGROUND: Coronary arteries without focal stenosis at angiography are generally considered non-flow-limiting. However, atherosclerosis is a diffuse process that often remains invisible at angiography. Accordingly, we hypothesized that in patients with coronary artery disease, nonstenotic coronary arteries induce a decrease in pressure along their length due to diffuse coronary atherosclerosis. METHODS AND RESULTS: Coronary pressure and fractional flow reserve (FFR), as indices of coronary conductance, were obtained from 37 arteries in 10 individuals without atherosclerosis (group I) and from 106 nonstenotic arteries in 62 patients with arteriographic stenoses in another coronary artery (group II). In group I, the pressure gradient between aorta and distal coronary artery was minimal at rest (1+/-1 mm Hg) and during maximal hyperemia (3+/-3 mm Hg). Corresponding values were significantly larger in group II (5+/-4 mm Hg and 10+/-8 mm Hg, respectively; both P<0.001). The FFR was near unity (0.97+/-0.02; range, 0.92 to 1) in group I, indicating no resistance to flow in truly normal coronary arteries, but it was significantly lower (0.89+/-0.08; range, 0.69 to 1) in group II, indicating a higher resistance to flow. In 57% of arteries in group II, FFR was lower than the lowest value in group I. In 8% of arteries in group II, FFR was <0.75, the threshold for inducible ischemia. CONCLUSION: Diffuse coronary atherosclerosis without focal stenosis at angiography causes a graded, continuous pressure fall along arterial length. This resistance to flow contributes to myocardial ischemia and has consequences for decision-making during percutaneous coronary interventions.

Fractional flow reserve to determine the appropriateness of angioplasty in moderate coronary stenosis: a randomized trial.

BACKGROUND: PTCA of a coronary stenosis without documented ischemia at noninvasive stress testing is often performed, but its benefit is unproven. Coronary pressure-derived fractional flow reserve (FFR) is an invasive index of stenosis severity that is a reliable substitute for noninvasive stress testing. A value of 0.75 identifies stenoses with hemodynamic significance. METHODS AND RESULTS: In 325 patients for whom PTCA was planned and who did not have documented ischemia, FFR of the stenosis was measured. If FFR was >0.75, patients were randomly assigned to deferral (deferral group; n=91) or performance (performance group; n=90) of PTCA. If FFR was <0.75, PTCA was performed as planned (reference group; n=144). Clinical follow-up was obtained at 1, 3, 6, 12, and 24 months. Event-free survival was similar between the deferral and performance groups (92% versus 89% at 12 months and 89% versus 83% at 24 months) but was significantly lower in the reference group (80% at 12 months and 78% at 24 months). In addition, the percentage of patients free from angina was similar between the deferral and performance groups (49% versus 50% at 12 months and 70% versus 51% at 24 months) but was significantly higher in the reference group (67% at 12 and 80% at 24 months). CONCLUSIONS: In patients with a coronary stenosis without evidence of ischemia, coronary pressure-derived FFR identifies those who will benefit from PTCA.

Stent placement to prevent restenosis after angioplasty in small coronary arteries.

BACKGROUND: Lesions in small-diameter vessels (<3 mm) define a group with distinct clinical and morphological characteristics. There is an inverse relationship between vessel size and angiographic restenosis rate. This study assessed whether stents reduce angiographic restenosis in small coronary arteries compared with standard balloon angioplasty. METHODS AND RESULTS: We randomly assigned 351 symptomatic patients needing dilatation of 1 native coronary vessel between 2.3 and 2.9 mm in size to angioplasty alone (n=182) or stent implantation (n=169). The primary end point was angiographic restenosis at 6 months. Secondary end points included death, myocardial infarction, bypass surgery, and target vessel revascularization in hospital and at 6 months. There were no significant differences between groups in terms of major in-hospital complications. There was a trend toward fewer in-hospital events in the stent group (3% versus 7.1% in angioplasty group, P=0.076). Crossovers to stent occurred in 37 patients (20.3%). Repeat angiography at 6-month follow-up was performed in 85.3% of patients. Angiographic restenosis occurred in 28% of the stent group and 32.9% of the angioplasty group (P=0.36). Target vessel revascularization was required in 17.8% versus 20.3% of patients (P=0.54), respectively. CONCLUSIONS: Stenting and standard coronary angioplasty are associated with equal restenosis rate in small coronary arteries. With a lower in-hospital complication rate, stenting may be a superior strategy in small vessels.

Coronary flow velocity reserve after percutaneous interventions is predictive of periprocedural outcome.

BACKGROUND: Because heterogeneous results have been reported, we assessed coronary flow velocity changes in individuals who underwent percutaneous transluminal coronary angioplasty (PTCA) and examined their impact on clinical outcome. METHODS AND RESULTS: As part of the Doppler Endpoints Balloon Angioplasty Trial Europe (DEBATE) II study, 379 patients underwent Doppler flow-guided angioplasty. All patients were evaluated according to their coronary flow velocity reserve (CFVR) results (> or =2.5 or < 2.5) at the end of the procedure. A CFVR < 2.5 after angioplasty was associated with an elevated baseline blood flow velocity in both the target artery and reference artery. CFVR before PTCA and CFVR in the reference artery were independent predictors of an optimal CFVR after balloon angioplasty (CFVR before PTCA: odds ratio [OR], 2.26; 95% confidence interval [CI], 1.57 to 3.24; CFVR in reference artery: OR, 1.90; 95% CI, 1.21 to 2.98; both P<0.001) and stent implantation (before PTCA: OR, 2.54; 95% CI, 1.47 to 4.36; reference artery: OR, 1.97; 95% CI, 1.07 to 3.87; both P<0.05). A low CFVR at the end of the procedure was an independent predictor of major adverse cardiac events (MACE) at 30 days (OR, 4.71; 95% CI, 1.14 to 25.92; P=0.034) and at 1 year (OR, 2.06; 95% CI, 1.16 to 3.66; P=0.014). After excluding MACE at 30 days, no difference in MACE at 1 year was observed between the patients with and without a CFVR < 2.5 at the end of the procedure. CONCLUSIONS: A low postprocedural CFVR was associated with a worse periprocedural outcome (which was related to microcirculatory disturbances), but there was no significant difference at late follow-up.

Randomized comparison of primary stenting and provisional balloon angioplasty guided by flow velocity measurement. Doppler Endpoints Balloon Angioplasty Trial Europe (DEBATE) II Study Group.

BACKGROUND: Coronary stenting improves outcomes compared with balloon angioplasty, but it is costly and may have other disadvantages. Limiting stent use to patients with a suboptimal result after angioplasty (provisional angioplasty) may be as effective and less expensive. METHODS AND RESULTS: To analyze the cost-effectiveness of provisional angioplasty, patients scheduled for single-vessel angioplasty were first randomized to receive primary stenting (97 patients) or balloon angioplasty guided by Doppler flow velocity and angiography (523 patients). Patients in the latter group were further randomized after optimization to either additional stenting or termination of the procedure to further investigate what is "optimal." An optimal result was defined as a flow reserve >2.5 and a diameter stenosis <36%. Bailout stenting was needed in 129 patients (25%) who were randomized to balloon angioplasty, and an optimal result was obtained in 184 of the 523 patients (35%). There was no significant difference in event-free survival at 1 year between primary stenting (86.6%) and provisional angioplasty (85.6%). Costs after 1 year were significantly higher for provisional angioplasty (EUR 6573 versus EUR 5885; P:=0.014). Results after the second randomization showed that stenting was also more effective after optimal balloon angioplasty (1-year event free survival, 93.5% versus 84.1%; P:=0. 066). CONCLUSIONS: After 1 year of follow-up, provisional angioplasty was more expensive and without clinical benefit. The beneficial value of stenting is not limited to patients with a suboptimal result after balloon angioplasty.

From research to clinical practice: current role of intracoronary physiologically based decision making in the cardiac catheterization laboratory.

Decisions regarding coronary interventions should be combined with objective evidence of myocardial ischemia. The most common physiologic approach utilizes hospital facilities outside the catheterization laboratory, requiring additional time and cost. With the introduction of sensor-tipped angioplasty guide wires, distal coronary flow velocity and pressure can be obtained in the cardiac catheterization laboratory, facilitating physiologically based decisions regarding the need for intervention. In the catheterization laboratory, physiologically significant stenoses can be characterized as having impaired post-stenotic coronary flow reserve < 2.0 and pressure-derived fractional flow reserve < 0.75, both variables related strongly to positive ischemic perfusion imaging or stress testing results. Deferring coronary interventions on the basis of normal translesional physiology is safe and is associated with a low rate (< 10%) of lesion progression over a 10-month follow-up period. Preliminary data indicate that excellent physiologic and anatomic end points after balloon angioplasty are associated with low (< 20%) restenosis rates at 6-month follow-up. Clinically relevant relations of in-laboratory physiology support the insight that physiologic, as much as or more than anatomic variables, ultimately determine the functional status of a patient. Current data suggest that an intracoronary physiologic approach complements coronary lumenology and appears to have important clinical and economic implications for patients undergoing invasive evaluation and treatment of coronary artery disease.

Coronary wedge pressure: a predictor of restenosis after coronary balloon angioplasty.

Coronary wedge pressure is the pressure recorded distal to a stenosis while the inflated balloon occludes the coronary artery during angioplasty. This pressure has been shown to reflect actual (visible) and potential (recruitable) collateral flow to the stenosed artery, distal to the angioplasty site. In 100 consecutive vessels (91 patients) for which coronary wedge pressure had been measured at the time of angioplasty, the long-term (7 +/- 3 months) angiographic results was evaluated. The overall angiographic restenosis rate was 37%. It was 52% (25 of 48) in arteries with a coronary wedge pressure greater than or equal to 30 mm Hg and 23% (12 of 52) in arteries with a coronary wedge pressure less than 30 mm Hg (p less than 0.01). The mean coronary wedge pressure was 30 +/- 10 mm Hg for vessels with restenosis and 26 +/- 9 mm Hg for those without restenosis (p less than 0.01). The prevalence of angiographically visible collateral flow was 42% and 29%, respectively (p = NS). Neither age, sex, presence of unstable angina, left ventricular function, number of diseased vessels nor initial and final transstenotic pressure gradient and degree of stenosis were significantly associated with the long-term outcome after angioplasty. Restenosis rate is significantly increased when coronary wedge pressure measured at the time of angioplasty is high (greater than or equal to 30 mm Hg). This suggests a negative influence of competitive collateral flow on long-term results of angioplasty.

Cardiac tamponade early after thrombolysis for acute myocardial infarction: a rare but not reported hemorrhagic complication.

Among 392 consecutive patients admitted for acute myocardial infarction and treated with thrombolytic drugs, 4 patients (1%) developed an early hemorrhagic pericardial effusion (without ventricular wall rupture) evolving within 24 h to cardiogenic shock consequent to cardiac tamponade. They all suffered from a large anterior myocardial infarction treated within 4 h after onset of symptoms with intravenous anisoylated plasminogen streptokinase activator complex (one case), recombinant tissue-type plasminogen activator (rt-PA) (two cases) or streptokinase (one case), anticoagulation with heparin (all cases) and aspirin (three cases). As soon as pericardial effusion was established by echocardiography, emergency percutaneous pericardiocentesis was performed at the bedside 20 +/- 6 h after thrombolytic therapy was started. This corrected immediately the clinical and hemodynamic status of each patient and a catheter was left in the pericardial space for 34 +/- 18 h. Thus, in the presence of unexplained clinical and hemodynamic deterioration occurring during the first 24 h after thrombolytic treatment of a large myocardial infarction, cardiac tamponade should be suspected. Immediate percutaneous pericardiocentesis followed by continuous drainage is a simple and definitive treatment for this complication.

Quantitative coronary angiography in predicting functional significance of stenoses in an unselected patient cohort.

OBJECTIVES: This study investigated the value of quantitative coronary angiography for predicting coronary flow reserve, as calculated from the transstenotic pressure gradient in a large, unselected patient cohort. BACKGROUND: In patients with extensive coronary artery disease, quantitative coronary angiographic findings fail to correlate with functional variables of coronary stenoses. New developments in pressure-monitoring wire technology permitted validation in humans of the concept of myocardial fractional flow reserve as assessed from coronary pressure measurements. METHODS: One hundred ten patients with normal left ventricular function were studied in the setting of coronary angioplasty. Quantitative coronary angiography was performed on-line using the ACA system. Myocardial and coronary fractional flow reserve were calculated from aortic and distal coronary pressures during maximal coronary hyperemia. RESULTS: When data before and after angioplasty were pooled, a curvilinear relation was found between myocardial fractional flow reserve and both diameter stenosis (r = 0.79) and minimal lumen diameter (r = 0.82), and a linear relation was found between myocardial fractional flow reserve and angiographic stenosis flow reserve (r = 0.78). Correlations between quantitative angiographic and pressure-derived indexes, although significant, were characterized by a large dispersion of the values of myocardial fractional flow reserve for a similar angiographic degree of stenosis. Nevertheless, the sensitivity and specificity of a minimal lumen diameter < 1.5 mm to predict myocardial fractional flow reserve < 0.72 were 96% and 89%, respectively. The corresponding values for a diameter stenosis > 50% were 93% and 85%, respectively. CONCLUSIONS: 1) In an unselected patient cohort, geometric indexes of stenosis severity derived from quantitative coronary angiography correlate significantly with physiologic variables, although these relations are imprecise in individual patients. 2) Nevertheless, the diagnostic accuracy of quantitative coronary angiography in predicting myocardial fractional flow reserve < 0.72 is high and allows its use for clinical decision making in the individual patient during diagnostic or interventional procedures.

Transstenotic coronary pressure gradient measurement in humans: in vitro and in vivo evaluation of a new pressure monitoring angioplasty guide wire.

OBJECTIVES: The present study was designed to investigate 1) the feasibility and accuracy of coronary pressure measurements with a novel 0.015-in. (0.038 cm) fluid-filled guide wire, and 2) the effect of the guide wire itself on stenosis hemodynamics. BACKGROUND: To assess the functional results of coronary angioplasty, measurements of the transstenotic pressure gradient have been advocated. However, this gradient is no longer routinely measured because it is not reliable when determined with the angioplasty catheter. METHODS: A fluid-filled 0.015-in. guide wire to be connected to a conventional pressure transducer was developed. Five wires were tested for their frequency response characteristics and for their accuracy in measuring hydrostatic pressure. In an in vitro model of stenosis (reference diameter 4 mm), the pressure gradient was determined at incremental flow levels for varying stenosis severity with and without a 0.015-in. guide wire through the narrowing. In 37 patients, the transstenotic pressure gradient was measured before and after angioplasty and compared with obstruction area and percent area stenosis as determined by quantitative coronary angiography. RESULTS: The correlation between the actual pressure and the pressure recorded by the guide wire was excellent (r = 0.98) despite a slight underestimation (-3 +/- 5%). Phasic pressure recordings were precluded by a long time constant of 16 +/- 4 s. The presence of the guide wire produced a significant overestimation (> 20%) of the pressure decrease only in cases of tight stenosis (> 90% area reduction). Furthermore, a theoretic model based on the fluid dynamic equation predicted that this overestimation was inversely proportional to the reference diameter of the vessel, yet was only slightly influenced by the flow. The lesion was crossed in all but one patient (97%) and pressure gradient was recorded throughout the study in 34 (94%) of 36 patients. The mean pressure gradient decreased from 30 +/- 19 before to 3 +/- 5 mm Hg after angioplasty (p < 0.01). A curvilinear relation was found between the pressure gradient and both percent area stenosis (r2 = 0.67) and obstruction area (r2 = 0.72). A sharp increase in pressure gradient was noted once the stenosis exceeded 75% area reduction. CONCLUSIONS: Mean transstenotic pressure gradients can be easily and reliably recorded with a 0.015-in. fluid-filled guide wire. This ability should facilitate the functional assessment of coronary stenoses of intermediate severity and of immediate postangioplasty results.