Improved myocardial function during exercise after successful percutaneous transluminal coronary angioplasty

Predictive value of early maximal exercise test and thallium scintigraphy after successful percutaneous transluminal coronary angioplasty

Restenosis of the dilated vessel after percutaneous transluminal coronary angioplasty can be detected by non-invasive procedures but their ability to predict later restenosis soon after a successful angioplasty as well as recurrence of angina has not been assessed. A maximal exercise test and myocardial thallium perfusion scintigraphy were, therefore, performed in 91 asymptomatic patients a median of 5 weeks after they had undergone a technically successful angioplasty. Primary success of the procedure was confirmed by the decrease in percentage diameter stenosis from 64(12)% to 30(13)% as measured from the coronary angiograms and in the trans-stenotic pressure gradient (normalised for mean aortic pressure) from 0.61(0.16) to 0.17(0.09). A clinical follow up examination (8.6(4.9) months later) was carried out in all patients and a late coronary angiogram obtained in 77. The thallium perfusion scintigram showing the presence or absence of a reversible defect was highly predictive for restenosis whereas the exercise test was not. The positive predictive value of an abnormal scintigram was 82% compared with 60% for the exercise test (ST segment depression/or angina or both at peak workload). Angina or a new myocardial infarction occurred in 60% of patients with abnormal and in 21% of patients with normal scintigrams.

Emergency coronary artery bypass graft surgery for threatened acute myocardial infarction related to coronary artery catheterization

In 20 patients undergoing cardiac catheterization, usually involving balloon-catheter dilation or streptokinase infusion, catheter-induced coronary artery intimal damage resulted in severe chest pain, electrocardiographic evidence of obstruction or dissection of a major coronary artery. These patients were surgically revascularized within 8 hours after the onset of the acute chest pain syndrome. Our experience with pharmacological and catheter-related manipulations to improve coronary blood flow after the ischemic episode but before operation suggested that the additional time spent in the catheterization laboratory was worthwhile. The injured coronary artery was the left anterior descending in 10 patients, the right in 8, the left main in 1 patient, and an obtuse marginal branch of the circumflex in 1. The average number of grafts per patient was 2.5; only 6 patients had single bypass grafts. In 5 patients, intraaortic balloon pumping was used either preoperatively or postoperatively. Inotropic support was used postoperatively in 5 patients, and 7 patients received lidocaine for ventricular irritability. Abnormal elevation of the serum isoenzyme of creatine kinase (CK-MB) was seen in 8 patients, and new Q waves were noted in 4 patients; 3 of these 4 patients with new Q waves also had abnormal serum CK-MB levels. Global ejection fraction obtained by the equilibrium-gated blood pool scan postoperatively was 60 +/- 3%, which was similar to the 62 +/- 3% obtained from the contrast-determined ventriculogram done preoperatively prior to the catheter-related injury. There were no early or late deaths, but morbidity was much higher in the group who had emergency coronary artery bypass grafting (CABG) compared with those who had elective CABG.(ABSTRACT TRUNCATED AT 250 WORDS)

Restenosis after transluminal coronary angioplasty detected with exercise-gated radionuclide ventriculography

Forty-one patients were evaluated with exercise-gated radionuclide ventriculography before and within 4 days after successful transluminal coronary angioplasty and 4 to 12 months later. Patients were subgrouped according to the degree of restenosis demonstrated angiographically at 4 to 12 months (Group I [n = 23]: less than or equal to 20%; Group II [n = 10]: greater than 20% but less than 50%; Group III [n = 8]: greater than or equal to 50%). Patients with abnormal findings on gated radionuclide ventriculography (less than 5 point increase in ejection fraction or wall motion deterioration) early after angioplasty were eventually found to have a greater degree of restenosis than were patients with normal findings (41.2 +/- 30.3 versus 19.0 +/- 25.4% restenosis, p less than 0.0001). The accuracy of abnormal radionuclide ventriculography in predicting 50% or greater restenosis was 73% immediately after angioplasty and 77% at the time of follow-up angiography. Gated radionuclide ventriculographic results were abnormal in 5% of Group I patients compared with 75% of Group III patients (p less than 0.01) early after angioplasty; at late follow-up, they were abnormal in 27% of Group I patients compared with 88% of Group III patients (p less than 0.01). Group I patients had a greater increase in ejection fraction than did Group III patients at early (+11.3 +/- 7.5 versus + 3.5 +/- 6.5 points, p less than 0.01) and late (+11.8 +/- 7.8 versus -1.9 +/- 8.7 points, p less than 0.0005) follow-up. It is concluded that gated radionuclide ventriculography is useful in predicting coronary restenosis after transluminal coronary angioplasty.

Percutaneous transluminal coronary angioplasty

Percutaneous transluminal coronary angioplasty appears to be an effective alternative to coronary artery bypass surgery in patients whose coronary artery anatomy is suitable--that is, an individual with single (or, at most, double) vessel coronary artery disease whose stenoses are proximal, discrete, subtotal, concentric and noncalcified. Since emergent coronary artery bypass surgery is required in 5% to 7% of patients even when angioplasty is attempted by an experienced physician, the patient should be an acceptable candidate for surgery from both a cardiac and noncardiac standpoint. Unfortunately, ideal angioplasty candidates are a distinct minority among those with coronary artery disease. If the procedure is reserved for ideal (or nearly ideal) candidates, the rate of success should approach 75% to 80%, and the incidence of major complications should be below 10%. Although the procedure appears to be effective in alleviating angina, it is unlikely that it will exert a beneficial effect on survival when compared to either medical therapy or coronary artery bypass surgery.

Relative cost of coronary angioplasty and bypass surgery in a one-vessel disease model

A national study was carried out to determine the relative costs of PTCA and CABG. Baseline clinical criteria for the 2 groups were similar. Data were collected in 186 sets for the PTCA group and 175 sets for the CABG group. Male patients make up 81% of the PTCA group and 80% of the CABG group. Mean hospital stay was 12 +/- 5 days in the CABG group, compared with 4 +/- 2 days in the PTCA group (p less than 0.001). The base charges for hospital and professional components of the CABG procedure were $15,580 +/- $2,159, whereas the same charges for the PTCA procedure were $5,315 +/- $2,159 (p less than 0.001). With an 80% primary success rate, which was the group mean success rate, the average dollar savings per PTCA procedure would be $7,149, or $7,149,000 per 1,000 cases. Thus, PTCA for revascularization in 1-vessel CAD is significantly more cost-effective than CABG in the short term.

Criteria for successful coronary angioplasty as assessed by alterations in coronary vasodilatory reserve

Currently, the success of coronary angioplasty is defined by anatomic criteria. Because of the known limitations of coronary arteriography, the translesional pressure gradient and coronary vasodilatory reserve were studied in 15 patients undergoing coronary angioplasty with the intent of defining a physiologically successful result. Coronary vasodilatory reserve was measured by a digital radiographic technique that has been previously validated against directly measured coronary sinus flow (r = 0.90, p less than 0.0001). A significant reduction in luminal stenosis from 71 +/- 12 to 34 +/- 11% (p less than 0.001) was accompanied by a reduction in translesional gradient from 47 +/- 19 to 21 +/- 12 mm Hg (p less than 0.001) and an increase in coronary vasodilatory reserve from 1.03 +/- 0.15 to 1.29 +/- 0.13 (p less than 0.001). There was a significant correlation between changes in luminal stenosis and changes in translesional gradient (r = 0.61, p less than 0.05), although a change of 20% or less in luminal diameter was accompanied by no change in pressure gradient. A more significant relation between changes in gradient and in coronary hyperemic reserve existed (r = 0.77, p less than 0.005). The relation was accurate even for small changes in gradient. Because saphenous vein bypass grafts have been shown to increase coronary vasodilatory reserve to at least 1.20, it is proposed that this physiologic criterion be used to define the success of revascularization by angioplasty. In patients in whom this value was achieved, translesional gradient was invariably 25% or less of ostial pressure and 20 mm Hg or less.(ABSTRACT TRUNCATED AT 250 WORDS)

Coumadin and aspirin in prevention of recurrence after transluminal coronary angioplasty: a randomized study

To determine the influence of adjunctive treatment with coumadin or aspirin on recurrence rate after percutaneous transluminal coronary angioplasty (PTCA), 248 patients in whom PTCA was assessed to be a primary success were randomized to either 325 mm aspirin daily or to coumadin treatment sufficient to maintain a prothrombin time 2 to 2.5 times the control value. The follow-up protocol included stress testing and coronary angiographic examinations 3 to 6 months after PTCA. All patients were followed for at least 9 months. Of the 122 patients randomized to coumadin 44 (36%) had recurrent stenoses as opposed to 34/126 (27%) of patients on aspirin, a difference that did not reach statistical significance at the .05 level. However, patients with at least a 6 month history of angina demonstrated a significantly different response to adjunctive treatment in that 19/43 (44%) of coumadin patients as compared with 10/48 (21%) of aspirin patients had recurrent stenoses (p less than .05). Thus, coumadin was not shown to be more effective than aspirin as adjunctive treatment after PTCA, while aspirin was shown to be superior to coumadin in patients with a longer history of angina.

Improvement in regional ventricular function after percutaneous transluminal coronary angioplasty

We performed atrial pacing and radionuclide ventriculography in 12 patients before and after percutaneous transluminal coronary angioplasty (PTCA). Successful dilatation was achieved in 9 patients while in 3 the procedure was unsuccessful. Atrial pacing before PTCA showed ischemic dysfunction of the region supplied by the narrowed coronary artery. Regional ejection fraction decreased by 36 +/- 12% during rapid atrial pacing, while global left ventricular ejection fraction fell by 11 +/- 7% with a secondary increase in end-diastolic and end-systolic ventricular volume with the onset of ischemia. After successful PTCA, ischemic dysfunction was ameliorated or abolished. Measurements made at identical heart rates showed that both global and in particular regional left ventricular ejection fraction were significantly higher after successful angioplasty and did not fall during the stress of atrial pacing. There was no improvement in regional or global LV function in patients in whom angioplasty was not successful. The study showed that nuclear ventriculography with the stress of graded atrial pacing was a useful method for analysing the immediate results of coronary angioplasty and for studying its effects on regional myocardial function.

Potential mechanisms of angioplasty

There are at least five potential mechanisms for enlarging the arterial lumen using the technique of percutaneous transluminal angioplasty. Each of these mechanisms is reviewed along with evidence from clinical or experimental angioplasty supporting or refuting an actual role for that mechanism in mechanical dilation of diseased vessels. Although plaque compaction is not plausible, each of the other four responses--redistributive modeling of plaque, embolization of plaque components, plastic stretching of the arterial wall, and phagocytic removal of plaque during healing after angioplasty--has been confirmed in at least some circumstances. Since the lesions probably differ in their biomechanical properties, we conclude that it is unlikely that a single mechanism will explain all of the successful dilations.

Coronary artery spasm at the site of angioplasty in the first 2 months after successful percutaneous transluminal coronary angioplasty

The clinical course of five patients manifesting coronary artery spasm at the site of previous successful percutaneous coronary angioplasty is reviewed. All patients showed this spasm on hemodynamically insignificant (less than 50% diameter narrowing) obstruction. Four patients did not respond to therapy with calcium channel antagonists and nitrates and subsequently developed recurrent stenosis. One patient died 2 months after angioplasty and 1 day after coronary bypass surgery. Pathologic study at the site of angioplasty revealed new artherosclerotic disease. Coronary spasm may occur during the healing period after coronary angioplasty and should be distinguished from fixed obstruction.

Determinants of transstenotic gradients observed during angioplasty: an experimental model

Pressure gradient measurement across a stenosis is used during angioplasty to aid catheter positioning and estimate dilatation efficacy. The angioplasty catheter itself, however, further reduces lumen size, and therefore augments the transstenotic gradient. To more precisely define the catheter influence on gradient, we derived a theoretical expression relating the measured gradient with the angioplasty catheter in situ to the "true" gradient; that is, the gradient in the absence of the angioplasty catheter. We then tested this theoretical construct in a canine femoral artery angioplasty model. Fifty-four measurements were performed using 23 separate, 3-mm-long, 40 to 70% stenoses. As predicted by the theoretic model, "true" gradient is compounded by the angioplasty catheter principally as a function of the angioplasty catheter diameter (Dc) and the stenosis diameter (Ds). The best-fit curve of data points relating "true" and compounded gradients to various Dc and Ds combinations can be expressed as: Measured gradient = K X true gradient, where K = 0.25 (e)4.47 (Dc divided by Ds) and e = 2.718. Thus, the transstenotic gradient measured at angioplasty overestimates "true" resting gradient in a predictable manner, which is dependent on the ratio of Dc to Ds.

Employment and recreation patterns in patients treated by percutaneous transluminal coronary angioplasty: a multicenter study

Employment and recreational patterns were analyzed in 279 patients who underwent percutaneous transluminal coronary angioplasty (PTCA) for treatment of symptomatic coronary artery disease. PTCA was successful in 180 patients (65%). When it was unsuccessful, coronary artery bypass graft surgery was usually performed (80%). Return-to-work rates were high irrespective of the outcome of PTCA. Of patients employed full-time or part-time before treatment, 98.5% of those who had successful PTCA alone and 97% of those whose PTCA was unsuccessful but who underwent uncomplicated coronary artery bypass surgery maintained or improved their work status. In a subgroup of men who had been employed in occupations requiring physical labor, 85% of the men whose PTCA was successful returned to work, compared with 68% of those whose PTCA was unsuccessful. The interval from attempted PTCA to return to work was significantly shorter in the successfully treated group; in patients with successful PTCA, the median time to return to work was 14 days, compared with 60 days in patients in whom PTCA was unsuccessful (p less than 0.001). During follow-up, patients with successful PTCA had less angina and were more active in recreational activities than patients who required alternative treatments.

Long-term exercise performance after percutaneous transluminal coronary angioplasty and coronary artery bypass grafting

In our first 169 consecutive patients admitted to undergo percutaneous transluminal coronary angioplasty (PTCA) serial bicycle ergometric exercise sessions were scheduled to assess long-term-exercise performance. In 160 of these 169 patients (95%) an average of seven ergometric measurements were available during a mean follow-up period of 29 months (range 1 to 60 months). Two groups were formed. One consisted of 132 patients in whom PTCA was successful and the other consisted of 28 patients with failure of PTCA who subsequently underwent coronary artery bypass grafting (CABG) either on an emergency basis (12 patients) or as an elective procedure (16 patients). Exercise performance was expressed as work capacity in watts according to the highest completed exercise stage. In the successful PTCA group the actual work capacities increased from 74 +/- 42 W (mean +/- SD) before PTCA to 122 +/- 47 W at the most recent follow-up examination. In patients who underwent emergency or elective CABG the respective figures were 73 +/- 34 or 65 +/- 37 W before surgery and 120 +/- 41 or 119 +/- 41 W at the most recent follow-up examination (p less than .005 for all preprocedure to postprocedure comparisons). Successful PTCA and CABG after failed PTCA improve work capacity significantly. Comparison of our results with those of surgical studies indicates that a failed attempt at PTCA before CABG does not compromise the functional outcome of the operation, regardless whether it is done on an emergency or on an elective basis.

Natural history of patients with single-vessel disease suitable for percutaneous transluminal coronary angioplasty

To permit comparison of percutaneous transluminal coronary angioplasty (PTCA) with conventional therapy, the clinical outcome was established in patients who would have been suitable candidates for PTCA but who presented before the technique was available. Coronary angiograms were reviewed of patients who met the following criteria: single-vessel disease with proximal subtotal coronary stenosis, chest pain of at least class II, and cardiac catheterization before 1981. Angiograms were evaluated according to established criteria for PTCA by an experienced angiographer. One hundred ten patients (2.1% of the patient population) were judged suitable for PTCA. Clinical and catheterization findings closely resembled those of patients in the national PTCA registry. Five years after catheterization, 97% of PTCA candidates treated medically were alive and 85% had not had myocardial infarction. Forty-six patients had coronary artery bypass surgery within 6 months of catheterization and 10 other patients had subsequent surgery. Five years after surgery, 91% were alive and 87% had not had myocardial infarction. At 6 months of follow-up, 78% of all patients had improved at least 1 functional class, and 86% of all patients working before catheterization were still employed. Functional capacity was well maintained during long-term follow-up (median 6.5 years, range 1.4 to 12.2). These data indicate that PTCA candidates have an excellent prognosis for survival, a low risk of infarction, and well-maintained functional capacity when revascularization is reserved for those with inadequate control of symptoms by medical therapy.

Should coronary arteries with less than 60% diameter stenosis be treated by angioplasty?

We evaluated all patients receiving percutaneous transluminal coronary angioplasty (PTCA) in the past year for mild stenosis (60% or less diameter narrowing, n = 64, group 1) and compared them with a random sample of 330 patients with greater than 60% stenosis (n = 66, group 2) treated during the same year. The degree of coronary stenosis before PTCA was 52 +/- 7% (mean +/- SD) in group 1 and 79 +/- 11% in group 2. The primary success rate was 90% (58 of 64 patients) in group 1 vs 86% (57 of 66 patients) in group 2. The incidence of complications requiring coronary surgery after PTCA failed was similar in both groups (3 of 64 in group 1, 4 of 66 in group 2), but there were four occurrences of myocardial infarction in group 1 and none in group 2 (p less than .05). Recurrence of stenosis was judged on the basis of objective data, 76% of which were angiographic data, in 97% of the patients with primary success. At a mean interval of 5 months with a mean follow-up period of 7 months, 17 of 58 patients (29%) with primary success in group 1 and 24 of 57 patients (42%) in group 2 developed restenosis. In group 1, restenosis was markedly more severe (73 +/- 15%) than initial stenosis (p less than .005), which was not the case in group 2. In conclusion, PTCA in mild stenosis has favorable primary and long-term results, yet carries the risk of myocardial infarction and emergency operation and may, in some cases, even accelerate the disease process.

Percutaneous transluminal angioplasty of a large septal artery

A severely stenotic, large-caliber, first septal artery was successfully dilated in a patient with refractory angina and nonsurgical, multivessel coronary artery disease. The success of this dilatation was related to favorable coronary anatomy and to the availability of a guidewire-directed dilatation catheter. Septal artery stenosis with or without surgically accessible stenoses in other coronary vessels represents a potential indication for percutaneous transluminal coronary angioplasty.

Status of the major epicardial coronary arteries 80 to 150 days after percutaneous transluminal coronary angioplasty. Analysis of 3 necropsy patients

Certain clinical and necropsy cardiac findings are described in 3 men who had percutaneous transluminal coronary angioplasty (PTCA) of the left anterior descending (LAD) coronary artery 80, 90, and 150 days before sudden death. Each patient had a decrease in the mean transstenotic coronary gradient (17, 38, and 43 mm Hg) and an angiographic increase in the LAD luminal diameter (55, 60, and 65%). At necropsy, the LAD coronary artery in the area of the PTCA in each patient was narrowed 76 to 95% in cross-sectional area by atherosclerotic plaques. No cracks in plaques or other lesions which may have resulted from the PTCA procedure were identified histologically in the LAD coronary artery of any patient.

Exercise radionuclide ventriculography in evaluating successful transluminal coronary angioplasty

To evaluate the ability of transluminal coronary angioplasty (TCA) to relieve myocardial ischemia, 44 patients with single vessel disease underwent exercise gated radionuclide ventriculography (GRNV) before and 2.8 +/- 1.3 days following angiographically successful TCA. Pre-TCA GRNV was abnormal in 11 of 14 patients with right coronary artery (RCA) stenosis and 24 of 30 with left anterior descending (LAD) stenosis. Following TCA there was an increase in exercise duration from 500 +/- 288 sec to 625 +/- 273 sec (P less than 0.001), and in maximum double product from (209 +/- 69) x 10(2) to (263 +/- 70) x 10(2) (P less than 0.001). The number of patients with stress-induced ST-T abnormalities decreased from 13 to 4 (P less than 0.05), and the number with chest pain during exercise decreased from 18 to one (P less than 0.001). Whereas resting ejection fraction was unchanged (0.58 +/- 0.10 vs 0.59 +/- 0.11) following TCA, the ejection fraction at peak exercise increased from 0.61 +/- 0.13 to 0.66 +/- 0.12 (P less than 0.001). Of 24 patients with resting abnormalities, regional wall motion improved in 13. In 22 of 31 patients with stress-induced asynergy, the wall motion response to exercise improved (P less than 0.001). Of 19 patients restudied angiographically and with exercise GRNV at 6-12 months, restenosis of greater than or equal to 50% had occurred in six, four of whom had abnormal studies. In six of whom the degree of stenosis of the dilated artery had remained less than or equal to 20% the exercise GRNV study remained normal. It is concluded that GRNV is helpful in documenting the improvement in resting left ventricular function and functional reserve in patients with angiographically successful TCA. In the limited number of patients with late follow-up studies, data suggest that GRNV may be a valuable test to detect restenosis.

Improved left ventricular diastolic filling in patients with coronary artery disease after percutaneous transluminal coronary angioplasty

Left ventricular (LV) diastolic filling is abnormal at rest in many patients with coronary artery disease (CAD), even in the presence of normal resting LV systolic function. To determine the effects of improved myocardial perfusion on impaired. LV diastolic filling, we studied 25 patients with one-vessel CAD by high-temporal-resolution radionuclide angiography before and after percutaneous transluminal coronary angioplasty (PTCA). No patient had ECG evidence of previous myocardial infarction. Despite normal regional and global LV systolic function at rest in all patents, LV diastolic filling was abnormal (peak LV filling rate [PFR] less than 2.5 end-diastolic volumes (EDV)/sec or time to PFR greater than 180 msec) in 17 of 25 patients. Twenty-three patients had abnormal LV systolic function during exercise. After successful PTCA, LV ejection fraction and heart rate at rest were unchanged, but LV ejection fraction during exercise increased, from 52 +/- 8% (+/- SD) to 63 +/- 5% (p less than 0.001). LV diastolic filling at rest improved: PFR increased from 2.3 +/- 0.6 to 2.8 +/- 0.5 EDV/sec (p less than 0.001) and time to PFR decreased from 181 +/- 22 to 160 +/- 18 msec (p less than 0.001). Thus, a reduction in exercise-induced LV systolic dysfunction after PTCA, reflecting a reduction in reversible ischemia, was associated with improved LV diastolic filling at rest. These data suggest that in many CAD patients with normal resting LV systolic function and without previous infarction, abnormalities of resting LV diastolic filling are not fixed, but appear to be reversible manifestations of impaired coronary flow.

Percutaneous transluminal coronary angioplasty: analysis of unsuccessful procedures as a guide toward improved results

Technical success in percutaneous transluminal coronary angioplasty (PTCA) is a function of patient selection, operator experience, and the capabilities of the angioplasty equipment employed. When unsuccessful PTCA occurs, it is the result of one of several factors: (1) a failure to cross the stenosis; (2) a failure to dilate the stenosis; (3) an ischemic complication; or (4) a late recurrence of the anginal syndrome. In this paper, we discuss the relative frequency of these types of failure, and the ways in which improvements in technique and/or equipment may be employed to improve the chance of a successful procedure.

Intracoronary streptokinase in clinical practice

The candidacy for streptokinase (SK) infusion was studied in 95 patients displaying ECG evidence of acute or impending infarction who were catheterized within 5 hours of the onset of chest pain. Intracoronary SK was administered to 84 patients in whom occlusions of the infarct-related vessel were identified, with early recanalization having been achieved in 74 (88%). Because of completeness of studies, a data base of 72 patients was employed for further analysis. Recanalization was sustained at follow-up in 45 of 55 patients (82%). Spontaneous thrombolysis was demonstrated at follow-up in five patients (8%) initially resistant to SK, and rethrombosis occurred in 10 patients (18%). Preservation of R waves relative to Q wave depth was limited to patients with less than 90% residual stenosis. Eight of nine patients with continuing thrombolysis and patients with recanalized occlusions of the left anterior descending coronary artery displayed more impressive increases in mean (+/- SEM) ejection fraction (47% +/- 4% to 53% +/- 5% [p less than 0.05], and 47% +/- 3% to 52% +/- 5, respectively). The ejection fraction also increased significantly in 15 patients with pre-SK values of less than 50% (41% +/- 2% to 48% +/- 3%; p less than 0.05). Ventricular function deteriorated in SK failures. Reperfusion arrhythmias occurred in 28 of 62 recanalized patients (45%). Minor bleeding tendencies were displayed in 18 of 72 patients (25%). Major hemorrhages, one of which may have been fatal, occurred in four patients (5.6%). Of 84 patients, four (4.7%) died, two of whom were in cardiogenic shock when first seen. In contrast, there were 11 deaths (11.8%) in a consecutive simultaneously enrolled series of 93 control patients with similar entry criteria (p less than 0.05). Two additional SK-treated patients died, 16 and 30 days after treatment, both more than a week after surgical revascularization. It is concluded that SK recanalization is a promising new therapy that may decrease mortality and preserve myocardial function in certain circumstances. Its efficacy in a setting closer to the mainstream of cardiologic practice extends the favorable experience issuing from earlier clinical investigations.

Cardiovascular research: decades of progress, a decade of promise

Mortality due to cardiovascular diseases has decreased more than 30 percent in the last 30 years, and this decline has accelerated so much that over 60 percent of it has occurred between 1970 and 1980. The past and present contributions of advances in cardiovascular research to this decline are reviewed. Although three have been significant research accomplishments, too many people still die of heart and blood vessel diseases. Continued emphasis must be placed on research in the areas of etiology and pathogenesis, on validating potentially beneficial research hypotheses, and on the translation and dissemination of research results to the health care practitioner and the public. Only then can our long-term goal, the prevention of cardiovascular disease, be fully realized.