Outcomes of elderly patients aged 80 and over with symptomatic, severe aortic stenosis: impact of patient's choice of refusing aortic valve replacement on survival.

BACKGROUND: Aortic valve replacement (AVR) can be performed safely in selected elderly patients with aortic stenosis (AS). However, the survival benefits of AVR over conservative treatment have not been convincingly demonstrated in AS patients aged above 80. AIM: To investigate the outcomes of patients aged 80 and over with symptomatic, severe AS and by analyzing the effects of patient's choice in either agreeing or refusing to undergo AVR, determine the survival benefits afforded by AVR. DESIGN: Cohort study. METHODS: Subjects aged 80 and over with severe symptomatic AS, diagnosed between 2001 and 2006 were segregated into three groups: subjects who underwent AVR (Group A); patients who were fit for AVR but declined surgery due to personal choice (Group B) and those who were not fit for surgery and were managed conservatively (Group C). Follow-up was conducted by out-patient attendances, review of medical records and telephone interviews. The primary endpoint was all-cause mortality. RESULTS: A total of 103 patients (86.0 +/- 4.2 years, 41% male) were identified and no patient was lost during follow-up. In Group A (n = 17), all 15 patients who underwent AVR were alive after 3.6 +/- 1.4 years follow-up and 2 died whilst awaiting AVR. Seventy-four percent of Group B (n = 24) and 76% of Group C (n = 62) died during follow-up. Group A had significantly better survival than B and C. (P < 0.01) Amongst patients fit for AVR with similar operative risks (Groups A and B), refusal to undergo surgery (hazard ratio 12.61, P = 0.001) was the only predictor of mortality in a multivariate model. CONCLUSION: For elderly AS patients fit for surgery, the patient's decision to refuse AVR is associated with a >12-fold increase in mortality risk. These findings have significant implications for informed decision-making when managing the fit, elderly patient with AS.

Limitation of coronary reserve after successful angioplasty is prevented by oral pretreatment with an alpha1-adrenergic antagonist.

Coronary vasoconstriction that occurs after percutaneous transluminal coronary angioplasty (PTCA) is abolished by intracoronary phentolamine. An impairment of coronary vasodilator reserve (CVR) has been observed < or = 7 days after successful PTCA. To ascertain whether pretreatment with the alpha1-adrenergic receptor blocker doxazosin could prevent the limitation of CVR after PTCA, we carried out a randomised, double-blind, controlled study on 26 patients with significant (> 75%) single vessel disease undergoing PTCA. Twelve patients received doxazosin 4 mg daily in addition to their standard treatment, while 14 patients received matching placebo, starting 11 days before PTCA. Myocardial blood flow (MBF) at baseline and after i.v. dipyridamole (0.56 mg/kg) was measured within 5 days after PTCA using positron emission tomography (PET) with oxygen-15-labelled water. Angioplasty was successful in all patients with a residual stenosis < or = 35%. At PET scanning, hemodynamic parameters were comparable in the two groups. In the territory subtended by the dilated artery, CVR was significantly higher in patients treated with doxazosin compared with those receiving placebo (2.78 +/- 0.1.21 vs. 1.95 +/- 0.68; p < 0.01). Conversely, CVR in the remote territories subtended by angiographically normal arteries was similar in the two groups (2.53 +/- 0.92 and 2.48 +/- 0.80, respectively; p = NS). Treatment with oral doxazosin in addition to standard antianginal therapy can prevent the impairment of CVR frequently observed despite successful PTCA.

Preinfarction angina as a predictor of more rapid coronary thrombolysis in patients with acute myocardial infarction.

BACKGROUND: When a myocardial infarction is preceded by angina, the infarct tends to be smaller than when there is no preinfarction angina. Prompt recanalization of the occluded infarct-related artery is crucial in limiting the size of the infarct. We prospectively studied the relation among preinfarction unstable angina, the speed of coronary reperfusion, and the size of the infarct in patients with acute myocardial infarction receiving thrombolytic therapy. METHODS: We compared 14 patients who had unstable angina during the week before myocardial infarction with 9 patients who had no preinfarction angina. Coronary arteriograms were obtained at base line and 15, 35, 55, and 90 minutes and 24 hours after the start of thrombolytic therapy. The size of the infarct was estimated on the basis of creatine kinase and creatine kinase MB levels, which were measured every 4 hours during the first 24 hours. RESULTS: Complete reperfusion (a flow of grade 3 according to the Thrombolysis in Myocardial Infarction classification) was achieved at 35 minutes in 64 percent of the patients with preinfarction angina but in none of those without preinfarction angina (P = 0.006); at 55 minutes in 86 percent and 38 percent, respectively (P = 0.05); and at 90 minutes in 86 percent and 50 percent, respectively (P = 0.14). The mean (+/- SD) time to reperfusion was 27 +/- 16 minutes in the group with preinfarction angina and 48 +/- 17 minutes in the group without preinfarction angina (P = 0.04); the peak creatine kinase levels were 1118 +/- 783 and 2395 +/- 1615 U per liter, respectively (P = 0.03); the peak creatine kinase MB levels were 102 +/- 67 and 251 +/- 186 U per liter, respectively (P = 0.009); and the 24-hour integrated creatine kinase MB levels were 1716 +/- 1171 and 4267 +/- 3252 U.liter-1 x 24 hours, respectively (P = 0.009). The time to reperfusion was positively correlated with the indexes of infarct size (r > or = 0.53, P < or = 0.02). CONCLUSIONS: In patients with acute myocardial infarction preceded by unstable angina, as compared with those without preinfarction angina, thrombolytic therapy resulted in more rapid reperfusion and smaller infarcts. Earlier myocardial reperfusion may thus account for the smaller infarct size in patients with preinfarction angina.

Early spontaneous intermittent myocardial reperfusion during acute myocardial infarction is associated with augmented thrombogenic activity and less myocardial damage.

OBJECTIVES: This study investigated the influence of early spontaneous intermittent reperfusion on the extent of myocardial damage and its relation to endogenous hemostatic activity. BACKGROUND: In the early phase of acute myocardial infarction coronary occlusion is often intermittent, even before thrombolytic therapy is administered. The relation between this phenomenon, myocardial damage and hemostatic activity is unknown. METHODS: Holter ST segment recording and pretreatment plasma tissue-type plasminogen activator (t-PA) antigen, plasminogen activator inhibitor-1 (PAI-1) antigen, prothrombin fragment F1 + 2 and soluble fibrin levels were measured in 57 patients with acute evolving myocardial infarction. Spontaneous intermittent myocardial reperfusion, defined as two or more episodes of transient resolution of ST segment elevation to within 0.05 mV of baseline, lasting > or = 1 min, before the start of recombinant t-PA (rt-PA) treatment was present in 28 patients (group 1) and absent in 29 (group 2). Left ventriculography and coronary angiography were performed 90 min after intravenous rt-PA administration. Plasma creatine kinase-MB fraction (CK-MB) levels were measured every 6 h for 24 h, and C-reactive protein levels were measured daily for 3 days. RESULTS: Group 1 had lower peak plasma CK-MB (141.9 +/- 28.3 vs. 203.8 +/- 23.3 IU/liter [mean +/- SEM], p < 0.014) and C-reactive protein levels (16 +/- 4 vs. 28 +/- 4 mg/liter on day 1; 26.6 +/- 5.5 vs. 61.8 +/- 14.4 mg/liter on day 2; 19.6 +/- 4.2 vs. 40.6 +/- 6.5 mg/liter on day 3, p < 0.012) and a higher left ventricular ejection fraction (62.9 +/- 4% vs. 51.1 +/- 5%, p < 0.04) than group 2. Group 1 had lower plasma t-PA antigen levels (15.6 vs. 27 micrograms/liter, p < 0.006) but higher prothrombin fragment F1 + 2 (1.8 vs. 1.1 nmol/liter, p < 0.003) and soluble fibrin levels (66.8 vs. 31 nmol/liter, p < 0.01). Coronary patency at 90 min was similar. CONCLUSIONS: Early spontaneous intermittent reperfusion during acute myocardial infarction is associated with augmented thrombogenic activity and less subsequent myocardial damage. This finding is consistent with a protective effect of intermittency on the myocardium and a procoagulant effect of spontaneous lysis on blood. It may also reflect a different rate of evolution of coronary thrombosis and myocardial infarction in patients with and those without spontaneous intermittent myocardial reperfusion.

Von Willebrand factor, plasminogen activator inhibitor-1 and C-reactive protein are markers of thrombolytic efficacy in acute myocardial infarction.

Plasma von Willebrand factor, plasminogen activator inhibitor activity and C-reactive protein were assessed as markers of coronary recanalisation in 30 patients with acute myocardial infarction receiving tissue-type plasminogen activator (t-PA). Blood samples were taken before t-PA (time 0), 4-hourly for 24 h and daily up to 72 h. A continuous electrocardiogram was recorded in the first 24 h. Coronary arteriography was performed 90 min and 24 h after the start of t-PA. Patients with a patent infarct artery (n = 17), compared to those with occluded artery (n = 13), showed a fall in von Willebrand factor from 0 to 24 h (p = 0.001), a greater fall in plasminogen activator inhibitor from 24 to 48 h (p = 0.04) and a fall in C-reactive protein from 48 to 72 h (p = 0.002). The accuracy of these indices compared favourably with time to peak plasma MB creatine kinase and > or = 50% resolution of maximal ST-deviation on the electrocardiogram. Thus, changes in plasma von Willebrand factor, plasminogen activator inhibitor and C-reactive protein during the first 3 days of myocardial infarction are indicative of thrombolytic efficacy. Their concordant behaviour may reflect a common regulatory mechanism.

Recovery-phase patterns of ST segment depression in the heart rate domain cannot distinguish between anginal patients with coronary artery disease and patients with syndrome X.

Continuous plots of ST segment depression related to heart rate during exercise and recovery (heart rate recovery loops) can differentiate patients with coronary artery disease from clinically normal subjects. To assess whether this method can also distinguish patients with angina and coronary artery disease from those with syndrome X (angina, positive exercise tests, and normal coronary arteries), we studied 75 patients with coronary artery disease and 30 patients with syndrome X. The average heart rate recovery loops for coronary artery disease and syndrome X patients followed similar counterclockwise loop rotations. Individual data analysis, however, showed that in coronary artery disease patients the loop rotation was counterclockwise in 66 (88%) and intermediate in nine (12%), while none had a clockwise loop nine (30%), and intermediate in nine (30%). Thus heart rate recovery loops cannot distinguish patients with angina and coronary artery disease from those with syndrome X.

Early coronary reperfusion blunts the procoagulant response of plasminogen activator inhibitor-1 and von Willebrand factor in acute myocardial infarction.

The effects of early coronary recanalization on the plasma levels of two procoagulant acute phase proteins, the fastacting plasminogen activator inhibitor and von Willebrand factor, were investigated in 24 patients with myocardial infarction receiving intravenous recombinant tissue-type plasminogen activator (rt-PA) within 6 h of the onset of symptoms. Coronary angiography was performed before and 90 min after the start of rt-PA infusion. Continuous electrocardiographic recordings and 4 h plasma creatine kinase MB isoenzyme (CK MB) were performed over the first 24 h. Plasma plasminogen activator inhibitor activity, von Willebrand factor and C-reactive protein were measured before rt-PA infusion, daily for the first 3 days and after 90 days. In the entire group, plasminogen activator inhibitor activity peaked at 24 h (day 1), representing a significant increase over values at all other times (p = 0.03). von Willebrand factor was higher in the first 2 days of infarction compared with after 90 days (p = 0.001). C-reactive protein peaked on day 2, with an eightfold increase over values on admission (p = 0.001). In the 16 patients with a patent infarct-related artery at 90 min, infarct size estimated by integrated 24 h CK MB, time for ST segment elevation to decrease to half-maximum and peak C-reactive protein were reduced significantly by more than twofold compared with values in the 8 patients with an occluded artery at 90 min. The patients with early recanalization also had lower plasminogen activator inhibitor activity on day 2 (p = 0.05) and day 3 (p = 0.02) and lower 0 to 72 h averaged von Willebrand factor (p = 0.01). Thus, early coronary recanalization curtails the response of plasminogen activator inhibitor activity and von Willebrand factor to myocardial infarction, most likely by reducing the extent of ischemia and necrosis and the consequent acute phase reaction. By blunting the early postinfarction procoagulant state, prompt recanalization may reduce the risk of thromboembolic complications in the first days after myocardial infarction.

Response of angiographically normal and atherosclerotic left anterior descending coronary arteries to acetylcholine.

Acetylcholine-induced constriction of human coronary arteries in vivo is commonly attributed to endothelial dysfunction. To examine the effects of 2 other important determinants of vascular responses--namely, agonist concentration and the segment of circulation under study--the diameters of proximal, middle and distal segments of the left anterior descending artery (LAD) and coronary sinus oxygen saturation were measured in 10 patients with angiographically normal coronary arteries (group 1) and in 7 patients with coronary atherosclerosis (group 2) after intracoronary acetylcholine was infused at concentrations from 10(-7)M to between 10(-4)M and 10(-2)M. In group 1, acetylcholine caused minor (less than or equal to 6%) but progressive dilatation of the LAD up to 10(-4)M, but constriction, particularly of the distal segments and tertiary branches, occurred at higher concentrations. Over the same concentration range, coronary sinus oxygen saturation rose progressively from a basal level of 36 +/- 3% to a maximum of 72 +/- 3% in the absence of changes in heart rate and blood pressure, suggesting marked progressive dilatation of resistance vessels. Concentrations greater than or equal to 10(-3)M caused intense constriction of distal epicardial vessels and, in some cases, anginal pain and objective signs of ischemia. Conversely, in group 2, acetylcholine (infused only up to 10(-4)M for ethical reasons) failed to cause significant changes in LAD diameter. These data suggest that the local acetylcholine concentration and coronary vascular segment under study may determine the observed response to at least an equivalent extent as does the presence or absence of coronary atherosclerosis, raising the question of whether a constrictor response to intracoronary acetylcholine reliably indicates the presence of coronary atherosclerosis.

Effectiveness of multiple bolus administration of tissue-type plasminogen activator in acute myocardial infarction.

The feasibility and possible advantages of intravenous bolus administration of recombinant tissue-type plasminogen activator (rt-PA) were investigated in 26 consecutive patients with early (less than 6 hours) evolving acute myocardial infarction. Either an intravenous infusion of 40 clot-lysis megaunits (cIMU) double-chain rt-PA over 1.5 hours followed by 20 cIMU over 5 hours (infusion group, n = 12) or 4 intravenous bolus injections of 10 cIMU at 20 minute intervals (bolus group, n = 14) were randomly administered. Coronary arteriography was performed before and at regular predefined intervals up to 90 minutes from the start of rt-PA administration, and at 24 hours. Acute recanalization of the infarct-related coronary artery was demonstrated in 7 of 12 patients (58%; 95% confidence interval 28 to 85%) in the infusion group and 11 of 14 patients (79%; 95% confidence interval 49 to 95%) in the bolus group (difference not significant). Two patients in the bolus group had reoccluded by 24 hours. Mean time from the start of rt-PA to patency of the infarct-related coronary artery was 39 +/- 6 (standard error of the mean) minutes in the infusion group and 28 +/- 6 minutes in the bolus group (p = 0.2). There were no significant differences in the minimum infarct-related coronary artery luminal diameter measured by computerized quantitative arteriography between the infusion group and the bolus group at 90 minutes or at 24 hours.(ABSTRACT TRUNCATED AT 250 WORDS)