Katherine M. Detre

A Randomized Comparison of Coronary-Stent Placement and Balloon Angioplasty in the Treatment of Coronary Artery Disease

BACKGROUND Coronary-stent placement is a new technique in which a balloon-expandable, stainless-steel, slotted tube is implanted at the site of a coronary stenosis. The purpose of this study was to compare the effects of stent placement and standard balloon angioplasty on angiographically detected restenosis and clinical outcomes. METHODS We randomly assigned 410 patients with symptomatic coronary disease to elective placement of a Palmaz-Schatz stent or to standard balloon angioplasty. Coronary angiography was performed at base line, immediately after the procedure, and six months later. RESULTS The patients who underwent stenting had a higher rate of procedural success than those who underwent standard balloon angioplasty (96.1 percent vs. 89.6 percent, P = 0.011), a larger immediate increase in the diameter of the lumen (1.72 +/- 0.46 vs. 1.23 +/- 0.48 mm, P < 0.001), and a larger luminal diameter immediately after the procedure (2.49 +/- 0.43 vs. 1.99 +/- 0.47 mm, P < 0.001). At six months, the patients with stented lesions continued to have a larger luminal diameter (1.74 +/- 0.60 vs. 1.56 +/- 0.65 mm, P = 0.007) and a lower rate of restenosis (31.6 percent vs. 42.1 percent, P = 0.046) than those treated with balloon angioplasty. There were no coronary events (death; myocardial infarction; coronary-artery bypass surgery; vessel closure, including stent thrombosis; or repeated angioplasty) in 80.5 percent of the patients in the stent group and 76.2 percent of those in the angioplasty group (P = 0.16). Revascularization of the original target lesion because of recurrent myocardial ischemia was performed less frequently in the stent group than in the angioplasty group (10.2 percent vs. 15.4 percent, P = 0.06). CONCLUSIONS In selected patients, placement of an intracoronary stent, as compared with balloon angioplasty, results in an improved rate of procedural success, a lower rate of angiographically detected restenosis, a similar rate of clinical events after six months, and a less frequent need for revascularization of the original coronary lesion.

Survival in Patients with Primary Pulmonary Hypertension: Results from a National Prospective Registry

OBJECTIVE To characterize mortality in persons diagnosed with primary pulmonary hypertension and to investigate factors associated with survival. DESIGN Registry with prospective follow-up. SETTING Thirty-two clinical centers in the United States participating in the Patient Registry for the Characterization of Primary Pulmonary Hypertension supported by the National Heart, Lung, and Blood Institute. PATIENTS Patients (194) diagnosed at clinical centers between 1 July 1981 and 31 December 1985 and followed through 8 August 1988. MEASUREMENTS At diagnosis, measurements of hemodynamic variables, pulmonary function, and gas exchange variables were taken in addition to information on demographic variables, medical history, and life-style. Patients were followed for survival at 6-month intervals. MAIN RESULTS The estimated median survival of these patients was 2.8 years (95% Cl, 1.9 to 3.7 years). Estimated single-year survival rates were as follows: at 1 year, 68% (Cl, 61% to 75%); at 3 years, 48% (Cl, 41% to 55%); and at 5 years, 34% (Cl, 24% to 44%). Variables associated with poor survival included a New York Heart Association (NYHA) functional class of III or IV, presence of Raynaud phenomenon, elevated mean right atrial pressure, elevated mean pulmonary artery pressure, decreased cardiac index, and decreased diffusing capacity for carbon monoxide (DLCO). Drug therapy at entry or discharge was not associated with survival duration. CONCLUSIONS Mortality was most closely associated with right ventricular hemodynamic function and can be characterized by means of an equation using three variables: mean pulmonary artery pressure, mean right atrial pressure, and cardiac index. Such an equation, once validated prospectively, could be used as an adjunct in planning treatment strategies and allocating medical resources.

Primary pulmonary hypertension. A national prospective study.

A national registry was begun in 1981 to collect data from 32 centers on patients diagnosed by uniform criteria as having primary pulmonary hypertension. Entered into the registry were 187 patients with a mean age (+/- SD) of 36 +/- 15 years (range, 1 to 81), and a female-to-male ratio of 1.7:1 overall. The mean interval from onset of symptoms to diagnosis was 2 years. The most frequent presenting symptoms included dyspnea (60%), fatigue (19%), and syncope (or near syncope) (13%). Raynaud phenomenon was present in 10% (95% of whom were female) and a positive antinuclear antibody test, in 29% (69% female). Pulmonary function studies showed mild restriction (forced vital capacity [FVC], 82% of predicted) with a reduced diffusing capacity for carbon monoxide (DLCO), and hypoxemia with hypocapnia. The mean (+/- SD) right atrial pressure was 9.7 +/- 6 mm Hg; mean pulmonary artery pressure, 60 +/- 18 mm Hg; cardiac index, 2.3 +/- 0.9 L/min X m2; and pulmonary vascular resistance index, 26 +/- 14 mm Hg/L/min X m2 for the group. Although no deaths or sustained morbid events occurred during the diagnostic evaluation of the patients, the typically long interval from initial symptoms to diagnosis emphasizes the need to develop strategies to make the diagnosis earlier.

Comparison of coronary bypass surgery with angioplasty in patients with multivessel disease. The Bypass Angioplasty Revascularization Investigation (BARI) Investigators.

BACKGROUND Coronary-artery bypass grafting (CABG) and percutaneous transluminal coronary angioplasty (PTCA) are alternative methods of revascularization in patients with coronary artery disease. We tested the hypothesis that in selected patients with multivessel disease suitable for treatment with either procedure, an initial strategy of PTCA does not result in a poorer five-year clinical outcome than CABG. METHODS Patients with multivessel disease were randomly assigned to an initial treatment strategy of CABG (n = 914) or PTCA (n = 915) and were followed for an average of 5.4 years. Analysis of outcome events was performed according to the intention to treat. RESULTS The respective in-hospital event rates for CABG and PTCA were 1.3 percent and 1.1 percent for mortality, 4.6 percent and 2.1 percent for Q-wave myocardial infarction (P < 0.01), and 0.8 percent and 0.2 percent for stroke. The five-year survival rate was 89.3 percent for those assigned to CABG and 86.3 percent for those assigned to PTCA (P = 0.19; 95 percent confidence interval of the difference in survival, -0.2 percent to 6.0 percent). The respective five-year survival rates free from Q-wave myocardial infarction were 80.4 percent and 78.7 percent. By five years after study entry, 8 percent of the patients assigned to CABG had undergone additional revascularization procedures, as compared with 54 percent of those assigned to PTCA; 69 percent of those assigned to PTCA did not subsequently undergo CABG. Among diabetic patients who were being treated with insulin or oral hypoglycemic agents at base line, a subgroup not specified by the protocol, five-year survival was 80.6 percent for the CABG group as compared with 65.5 percent for the PTCA group (P = 0.003). CONCLUSIONS As compared with CABG, an initial strategy of PTCA did not significantly compromise five-year survival in patients with multivessel disease, although subsequent revascularization was required more often with this strategy. For treated diabetics, five-year survival was significantly better after CABG than after PTCA.

Restenosis after percutaneous transluminal coronary angioplasty (PTCA): A report from the PTCA registry of the national heart, lung, and blood institute

The results of follow-up angiography in patients from 27 clinical centers enrolled in the PTCA Registry were analyzed to evaluate restenosis after PTCA. Of 665 patients with successful PTCA, 557 (84%) had follow-up angiography (median follow-up 188 days). Restenosis, defined as an increase of at least 30% from the immediate post-PTCA stenosis to the follow-up stenosis or a loss of at least 50% of the gain achieved at PTCA, was seen in 187 patients (33.6%). The incidence of restenosis in patients who underwent follow-up angiography was highest within the first 5 months after PTCA. Restenosis was found in 56% of patients with definite or probable angina after PTCA and in 14% of patients without angina after PTCA. Twenty-four percent of patients with restenosis did not have either definite or probable angina. Multivariate analysis selected 4 factors associated with increased rate of restenosis: male sex, PTCA of bypass graft stenosis, severity of angina before PTCA and no history of MI before PTCA.

Percutaneous transluminal coronary angioplasty in 1985-1986 and 1977-1981. The National Heart, Lung, and Blood Institute Registry

In August 1985, the Percutaneous Transluminal Coronary Angioplasty Registry of the National Heart, Lung, and Blood Institute reopened at its previous sites to document changes in angioplasty strategy and outcome. The new registry entered 1802 consecutive patients who had not had a myocardial infarction in the 10 days before angioplasty. Patient selection, technical outcome, and short-term major complications were compared with those of the 1977 to 1981 registry cohort. The new-registry patients were older and had a significantly higher proportion of multivessel disease (53 vs. 25 percent, P less than 0.001), poor left ventricular function (19 vs. 8 percent, P less than 0.001), previous myocardial infarction (37 vs. 21 percent, P less than 0.001), and previous coronary bypass surgery (13 vs. 9 percent, P less than 0.01). The new-registry cohort also had more complex coronary lesions, and angioplasty attempts in these patients involved more multivessel procedures. Despite these differences, the in-hospital outcome in the new cohort was better. Angiographic success rates according to lesion increased from 67 to 88 percent (P less than 0.001), and overall success rates (measured as a reduction of at least 20 percent in all lesions attempted, without death, myocardial infarction, or coronary bypass surgery) increased from 61 to 78 percent (P less than 0.001). In-hospital mortality for the new cohort was 1 percent, and the nonfatal myocardial infarction rate was 4.3 percent. Both rates are similar to those for the old registry. The long-term efficacy of current angioplasty remains to be determined.

Coronary Angioplasty in Diabetic Patients The National Heart, Lung, and Blood Institute Percutaneous Transluminal Coronary Angioplasty Registry

BACKGROUND Patients with diabetes mellitus are at increased risk of cardiovascular disease. To date, the baseline status and subsequent outcomes of diabetic coronary angioplasty (percutaneous transluminal coronary angioplasty, or PTCA) patients with advanced atherosclerotic disease and with procedures performed across North America have not been well characterized. METHODS AND RESULTS Data on baseline clinical and angiographic characteristics and short- and long-term outcomes of 281 diabetic and 1833 nondiabetic PTCA patients in the multicenter National Heart, Lung, and Blood Institute 1985-1986 PTCA Registry were analyzed. Diabetic patients were older, were more likely to be female, and had more comorbid baseline conditions, triplevessel disease, and atherosclerotic lesions. Angiographic success and completeness of revascularization did not differ significantly, yet diabetic patients experienced more in-hospital death (women) and nonfatal myocardial infarction. Nine-year mortality was twice as high in diabetic patients (35.9% versus 17.9%). Similarly, 9-year rates of nonfatal myocardial infarction (29.0% versus 18.5%), bypass surgery (36.7% versus 27.4%), and repeat PTCA (43.7% versus 36.5%) were higher in diabetics than in nondiabetics. In multivariate analysis, diabetes remained a significant predictor of decreased 9-year survival and other untoward events. CONCLUSIONS Compared with nondiabetic PTCA patients, diabetic patients have more extensive and diffuse atherosclerotic disease. Despite similar probability of angiographic success, diabetic patients are more likely to suffer in-hospital death(women) and nonfatal myocardial infarction. Long-term survival and freedom from myocardial infarction and coronary revascularization is also reduced in diabetic PTCA patients. Whether PTCA or coronary bypass surgery is more suitable for these patients is currently under investigation.

Observer agreement in evaluating coronary angiograms.

The reliability of interpretation of coronary arteriography as a diagnostic tool was investigated in a sub study of the VA Cooperative Study of Surgical Treatment for Coronary Arterial Occlusive Disease. Twenty two physicians with varying levels of experience read 13 cine angiograms — blind — on two different oc casions. Analysis of inter- and intraobserver variability showed that angiographic items about which observers were most inconsistent from one reading to the other had the largest interobserver disagreement as well. They were the distal portions of the left anterior descending and left circumflex arteries. Among the items on which there was most consistent agreement — namely, the right main coronary artery and presence of ven tricular aneurysm — there was most often agreement between observers as well. When individual readers were evaluated, some observers were far more consistent in their own readings of all the angiographic items than others. This intraobserver agreement in turn correlated fairly well with how often they agreed with the other observers and with how much experience they reported having in reading coronary cineangiograms.

Treatment of chronic stable angina. A preliminary report of survival data of the randomized Veterans Administration cooperative study.

We evaluated the effect of saphenous-vein-bypass grafting on survival in patients with chronic stable angina by comparing medical and surgical treatment in a large-scale, prospective randomized study. Excluding patients with left-main-coronary-artery disease who have already been reported, a total of 596 patients were entered into this study; when randomized into a medical group (310 patients) and a surgical group (286 patients), entry clinical and angiographic base lines were comparable. Operative mortality at 30 days was 5.6 per cent. At an average of one year after operation, 69 per cent of all grafts were patent, and 88 per cent of the surgical patients had atleast one patent graft. There was no statistically significant difference in survival, at a minimal follow-up interval of 21 months, between patients treated medically and those treated with saphenous-vein-bypass grafting. At 36 months, 87 per cent of the medical group and 88 per cent of the surgical group were alive.

Incidence and consequences of periprocedural occlusion. The 1985-1986 National Heart, Lung, and Blood Institute Percutaneous Transluminal Coronary Angioplasty Registry.

Of 1,801 patients in the 1985-1986 Percutaneous Transluminal Coronary Angioplasty (PTCA) Registry, 122 (6.8%) had periprocedural occlusion (4.9% in the catheterization laboratory, 1.9% outside the laboratory). Baseline patient factors independently associated with increased occlusion rates included triple-vessel disease, high risk status for surgery, and acute coronary insufficiency. Lesion characteristics showing significant positive association included severe stenosis before PTCA, diffuse or multiple discrete morphology, thrombus, and collateral flow from the lesion. Intimal tear and dissection were also very strongly associated with occlusion. Sixty patients (49%) had a transient occlusion that was reopened with PTCA, 43 (35%) were not redilated and managed with bypass surgery, and 19 (16%) were not redilated and managed medically. In-hospital mortality was 5% in each of these treatment groups, compared with 1% in occlusion-free patients. In-hospital infarction rates ranged from 27% in patients with transient occlusion to 56% in the patients managed with surgery, compared with 2% in patients without occlusion. During 2 years of follow-up, somewhat increased mortality continued in patients with occlusion, whereas follow-up infarction rates were comparable for all patients regardless of occlusion. Patients with an occlusion that was reopened or managed medically had increased rates of surgery during follow-up. Rates of repeat PTCA were comparable (about 23% by 2 years) in patients with transient occlusion and those without occlusion. Occlusion remains a serious complication of angioplasty and is associated most strongly with major events and surgical procedures that occur during the in-hospital period.